<PAGE>

                                                                   Exhibit 10.21

                                 DEED OF LEASE



                                    BETWEEN



                 PARKRIDGE FIVE ASSOCIATES LIMITED PARTNERSHIP



                                  AS LANDLORD,



                                      AND



                              MUSICMAKER.COM,INC.



                                   AS TENANT



             _____________________________________________________

             _____________________________________________________



                    For 20,566 20,000 rentable square feet




                               In Parkridge Five



                         Dated: September  _____, 1999
<PAGE>

                                 DEED OF LEASE

     THIS DEED OF LEASE (this "Lease") is made as of the _____ day of September,
1999 (the "Date of Lease"), by Parkridge Five Associates Limited Partnership, a
Virginia Limited Partnership ("Landlord"), and Musicmaker.com, Inc., a Delaware
corporation ("Tenant").

     NOW, THEREFORE, WITNESSETH, that for and in consideration of the mutual
covenants and promises contained herein and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
Landlord and Tenant, intending legally to be bound, hereby covenant and agree as
set forth below.

                                   ARTICLE I
                         FUNDAMENTAL LEASE DEFINITIONS

     The following terms, when used herein, shall have the meanings set forth
below.

     1.1   Landlord: Parkridge Five Associates Limited Partnership.
           --------

     1.2   Landlord's Address:  c/o Walker and Company, 12007 Sunrise Valley
           -------------------
Drive, Suite 400, Reston, Virginia, 20191.

     1.3   Landlord's Representative:  Christopher W. Walker.
           --------------------------

     1.4   Manager:  Walker Management, Inc., 12007 Sunrise Valley Drive, Suite
           --------
400, Reston, Virginia, 20191.

     1.5   Tenant: Musicmaker.com, Inc.
           ------

     1.6   Tenant Address: Current: 1831 Weihle Avenue, Suite 128, Reston, Va.
           --------------
20190, after Commencement Date: 10780 or 10790 Parkridge Boulevard, Concourse
Level, Reston, Va. 20191.

     1.7   Tenant's Representative: Mr. Bruce Block.
           -----------------------

     1.8   Guarantor: N/A.
           ---------

     1.9   Guarantor's Address: N/A.
           -------------------

     1.10  Building:  The building containing approximately 203,492  square feet
           ---------
shown on Exhibit A-1 attached hereto and made a part hereof, and all
alterations, additions, improvements, restorations or replacements now or
hereafter made thereto, located at 10780/10790 Parkridge Boulevard, Reston,
Fairfax County, Virginia, 20191, in the Parkridge Center.

     1.11  Premises:  Approximately 20,566  rentable square feet located on the
           ---------
Concourse Level, Suite TBD of the Building as outlined in Exhibit A-2 attached
hereto and made a part hereof, subject to verification if caused to measured by
either party hereto, in accordance with the standards as set forth in ANSI
Z65.1-1996/BOMA, as promulgated by the Building Owners and Managers Association.

     1.12  Term: Ten (10) years, zero (-0-) months and zero (-0-) days, subject
           -----
to adjustment as set forth in Article III.

     1.13  Commencement Date: Earlier of Substantial Completion of the Premises
           -----------------
or January 1, 2000 but excluded for  delays caused by Base Building not being
able to support Tenant Improvements and subject to adjustment as set forth in
Article III.

     1.14  Expiration Date: December 31, 2009, subject to adjustment as set
           ----------------
forth in Article III.

     1.15  Basic Rent:  Approximately $27.69 for each rentable square foot of
           -----------
the Premises during the first Lease Year and increased annually as set forth in
Exhibit A-3.

     1.16  Lease Year:  Each successive twelve (12) month period following the
           -----------
Commencement Date.

     1.17  Expense Stop: Year 2000 actual expenses, adjusted for extraordinary
           -------------
items.

     1.18  Tenant's Proportionate Share:  Rentable floor area of the Premises
           -----------------------------
divided by rentable floor area of the Building, or ten point zero-eight percent
(10.08%), subject to verification as set forth in Section 1.11 above.
<PAGE>

     1.19  Security Deposit:  $620,000, due by October 15, 1999 .
           -----------------

     1.20  Landlord's Architect: N/A.
           ---------------------

     1.21  Tenant Finish Work Submission Date: N/A.
           -----------------------------------

     1.22  Broker(s):  Landlord's: N/A; Tenants: Trammell Crow Real Estate
           ----------
Services, Inc.

     1.23  Land:  The land on which the Building is located as described in
           -----
Exhibit A-1.

     1.24  Common Area:  All areas, improvements, facilities and equipment from
           ------------
time to time designated by Landlord for the common use or benefit of Tenant,
other tenants of the Building and their Agents, including, without limitation,
roadways, entrances and exits, landscaped areas, open areas, park areas,
exterior lighting, service drives, loading area, pedestrian walkways, sidewalks,
atriums, courtyards, concourses, stairs, ramps, washrooms, maintenance and
utility rooms and closets, exterior utility lines, hallways, lobbies, elevators
and their housing and rooms, common window areas, common walls, common ceilings,
common trash areas and parking facilities.

     1.25  Permitted Use:  General office and music distribution.
           --------------

     1.26  Agents:  Officers, partners, directors, employees, agents, licensees,
           -------
customers, invitees, and contractors.

     1.27  Substantial Completion:  As defined in Exhibit B-1.
           -----------------------

     1.28  Interest Rate:  Per annum interest rate listed as the base rate on
           --------------
corporate loans at large U.S. money center commercial banks as published from
time to time under "Money Rates" in the Wall Street Journal plus two percent
(2%), with a minimum rate of 12% per annum (1% per month), but in any event not
greater than the maximum rate permitted by law.  In the event the Wall Street
Journal ceases to publish such rates, Landlord shall choose at Landlord's
reasonable  discretion a similar publication which publishes such rates.

     1.29  Mortgage:  Any mortgage, deed of trust, security interest or title
           ---------
retention interest affecting the Building or the Land.

     1.30  Mortgagee:  The holder of any note or obligation secured by a
           ----------
mortgage, deed of trust, security interest or title retention interest affecting
the Building or the Land, including, without limitation, lessors under ground
leases, sale-leasebacks and lease-leasebacks.

     1.31  Exhibits and Addenda:  The Exhibits and Addenda listed below in this
           ---------------------
section are incorporated in this Lease by reference and are to be construed as
part of this Lease:

          Exhibit A-1    - Plat Showing Land and Building
          Exhibit A-2    - Plan Showing the Premises
          Exhibit A-3    - Rent Schedule
          Exhibit B-1    - Work Agreement
          Exhibit B-2    - Base Building Shell
          Exhibit C      - Rules and Regulations
          Exhibit D      - Holidays
          Exhibit E      - Cleaning Specifications
          Exhibit F      - Low Voltage Cabling
          Exhibit G      - SMART Arbitration Rules
          Addendum One   - UPS Generator/Satellite Dish
          Addendum Two   - Right of First Refusal
          Addendum Three - Option to Renew

                                   ARTICLE II

                                  THE PREMISES

     2.1   Description of the Premises.  Landlord hereby leases to Tenant,
           ----------------------------
subject to and with the benefit of the provisions of the Lease and subject to
existing easements, agreements, rights and encumbrances of record, which
Landlord covenants will not unreasonably interfere with Tenant's use and
enjoyment of the Premises, the Premises, together with the right to use, subject
to the rules and regulations of Landlord attached as Exhibit C, the parking
areas, Common Area, walkways, and driveways from time to time located on the
Land.

     2.2  Landlord's Rights Reserved.  Landlord reserves unto itself, and its
          ---------------------------
Agents, the right to use, maintain, repair and replace the Common Area,
including without limitation, the elevators, hallways, staircases, shaftways,
<PAGE>

and other common facilities in the Building, and the right to maintain, use,
construct, repair, and replace pipes, ducts, wires, meters and any other
equipment, machinery, apparatus and fixtures therein as well as within or
leading through the Premises, where possible in such a manner as will not cause
unreasonable interference with Tenant's use and subject to Tenant's security
requirements and, to the extent practicable, such items shall be located above
the ceilings, behind the walls, or within the columns of the Premises. Landlord
expressly reserves the right permanently to change, modify or eliminate, or
temporarily to close, any portion of the Common Area, provided the same does not
unreasonably interfere with Tenant's use and enjoyment of the Premises.  In
addition to the other rights of Landlord under this Lease, Landlord reserves the
right (i) to change the street address and/or name of the Building, (in which
event Landlord shall reimburse Tenant for all reasonable out of pocket expenses
in connection with replacing stationary, business cards and similar items, (ii)
to maintain exclusive control over the use of the roof and exterior walls of the
Building.  Landlord may exercise any or all of the foregoing rights without
being deemed to be guilty of an eviction, actual or constructive, or a
disturbance or interruption of the business of Tenant or Tenant's use or
occupancy of the Premises.

                                  ARTICLE III

                                      TERM

     The Term shall commence on the Commencement Date and expire at midnight on
the Expiration Date.   If Substantial Completion occurs prior to January 1,
2000, excluding delays caused by base building not able to support Tenant
Improvements  then the Commencement Date shall be such date upon which the
Premises are Substantially Complete   If requested by Landlord, Tenant shall
within fifteen (15) days after such request sign a declaration in recordable
form acknowledging the Commencement Date and the Expiration Date.

                                   ARTICLE IV

                                      RENT

     4.1  Basic Rent.  Tenant shall pay to Landlord the Basic Rent as specified
          -----------
in Section 1.15, increased annually as set forth on Exhibit A-3.  The first
month's rent shall be due October 1, 1999.

     4.2  Payment of Basic Rent.  Basic Rent for each Lease Year shall be
          ----------------------
payable in equal monthly installments, in advance, without demand, notice,
deduction, offset or counterclaim, on or before the first day of each and every
calendar month during the Term; provided, however, that the installment of the
Basic Rent payable for the first full calendar month of the Term (and, if the
Commencement Date occurs on a date other than on the first day of a calendar
month, Basic Rent prorated from such date until the first day of the following
month) shall be due and payable on the full execution and delivery of this
Lease.  Tenant shall pay the Basic Rent and all Additional Rent, by good check
or in lawful currency of the United States of America, to Landlord at Landlord's
Address, or to such other address or in such other manner as Landlord from time
to time specifies by written notice to Tenant.  Any payment made by Tenant to
Landlord on account of Basic Rent may be credited by Landlord to the payment of
any late charges then due and payable and to any Basic Rent or Additional Rent
then past due before being credited to Basic Rent currently due.

     4.3  Additional Rent.  All sums payable by Tenant under this Lease, other
          ----------------
than Basic Rent, shall be deemed "Additional Rent," and, unless otherwise set
forth herein, shall be payable in the same manner as set forth above for Basic
Rent and Landlord shall have the same rights and remedies in the collection of
Additional Rent as Landlord has in the collection of Basic Rent.  Basic Rent and
Additional Rent are collectively referred to hereinafter as "Rent."

     4.4  Late Payment.  If Tenant fails to pay any Rent within five (5) days
          -------------
after such Rent becomes due and payable, Tenant shall pay to Landlord a late
charge of five percent (5%) of the amount of such overdue Rent.  In addition,
any such late Rent payment shall bear interest from the date such Rent became
due and payable to the date of payment thereof by Tenant at the Interest Rate.
Such late charge and interest shall be due and payable within five (5) business
days  after written demand from Landlord.

     4.5  Pre Commencement Date Occupancy. Tenant may occupy all or a portion of
          --------------------------------
the Premises prior to the Commencement Date, but must pay tenant's

                                       4
<PAGE>

Proportiionate Share of the Landlord's Operating Expenses as defined in Article
1.18 and Article VI hereof for the period of such occupancy.



                                   ARTICLE V
                                SECURITY DEPOSIT

     Simultaneous with the execution of this Lease, Tenant shall deposit the
Security Deposit with Landlord, which shall be held by Landlord, without
obligation for interest for a letter of credit or surety bond, as security for
the performance of Tenant's obligations and covenants under this Lease.  It is
expressly understood and agreed that such deposit is not an advance rental
deposit or a measure of Landlord's damages in case of an Event of Default.  If
an Event of Default shall occur or if Tenant fails to surrender the Premises in
the condition required by this Lease, Landlord shall have the right (but not the
obligation), and without prejudice to any other remedy which Landlord may have
on account thereof, to apply all or any portion of the Security Deposit to cure
such default or to remedy the condition of the Premises.  If Landlord so applies
the Security Deposit or any portion thereof before the Expiration Date or
earlier termination of the Lease, Tenant shall deposit with Landlord, upon
demand, the amount necessary to restore the Security Deposit to its original
amount.  If Landlord shall sell or transfer its interest in the Building,
Landlord shall  transfer the Security Deposit to such purchaser or transferee,
in which event Tenant shall look solely to the new landlord for the return of
the Security Deposit.  Although the Security Deposit shall be deemed the
property of Landlord, any remaining balance of the cash Security Deposit not
otherwise applied hereunder shall be returned to Tenant at such time after the
Expiration Date or earlier termination of this Lease that all of Tenant's
obligations under this Lease have been fulfilled.   A cash Security Deposit
shall be held in an interest bearing account in a Federally insured financial
institution, or posted as an unconditional , irrevocable letter of credit  or
equivalent surety bond.  Security Deposit shall be reduced by $60,000 per year
if Tenant is not in Default.  If Tenant utilizes a letter of credit or
equivalent surety bond for its Security Deposit, Landlord must receive a
replacement letter of credit or equivalent surety bond at least two (2) weeks
prior to the expiration of the current letter of credit or surety bond,
otherwise Landlord may cash the expiring letter of credit or redeem the bond,
and hold the Security Deposit as a cash deposit as set forth herein.

                                   ARTICLE VI
                               OPERATING EXPENSES

     6.1  Tenant's Proportionate Share.  For each Lease Year throughout the
          -----------------------------
Term, Tenant covenants and agrees to pay to Landlord Tenant's Proportionate
Share of Landlord's Operating Expenses of the amount, if any, by which the total
of Landlord's Operating Expenses (as defined in Section 6.2 hereof) for said
Lease Year or portion thereof exceeds the amount of the Expense Stop.  In the
event that the Commencement Date or the Expiration Date are other than the first
day of a calendar year then Tenant's Proportionate Share of such excess of
Landlord's Operating Expenses shall be adjusted to reflect the actual period of
occupancy during the calendar year.

     6.2  Landlord's Operating Expenses Defined.  As used herein, the term
          --------------------------------------
"Landlord's Operating Expenses" shall mean all reasonable expenses and costs of
every kind and nature which Landlord incurs because of or in connection with the
ownership, maintenance, management and operation of the Land, the Building and
the Common Area including all additional costs and expenses of operation,
management and maintenance of the Land, the Building and the Common Area or, at
the very minimum, which Landlord determines that it would have paid or incurred
during any calendar year if the Building had been no less than ninety-five
percent (95%) occupied.  Landlord's Operating Expenses shall include, without
limitation, all costs, expenses and disbursements incurred or made in connection
with the following:

          (i)   Wages and salaries of all employees, whether employed by
Landlord or the Building's management company, engaged in the operation and
maintenance or security of the Land, the Building, and the Common Area, and all
costs related to or associated with such employees or the carrying out of their
duties, including uniforms and their cleaning, taxes, auto allowances and
insurance and benefits (including, without limitation, contributions to pension
and/or profit sharing plans and vacation or other paid absences), but with
respect to employees who do not devote their full time to the Land, Building and
Common Area, Operating Expenses shall only include, with respect to such
employees, the percentage of such costs equivalent to the percentage of time
which such employees devote to the Land, Building and Common Area;

          (ii)  All supplies and materials, including janitorial and lighting
supplies, used directly in the operation and maintenance of the Building, the
Land and the Common Area;

          (iii)     All utilities, including, without limitation, electricity,
telephone, water, sewer, power, gas, heating, lighting and air conditioning for
the Land, the Building and the Common Area, except to the extent such utilities
are charged directly to or paid directly by a tenant of the Building.  In
addition to standard building utilities, Tenant shall pay the cost of sub-
metered electrical usage for non-office use of the Premises and shall have the

                                       5
<PAGE>

option to convert the rental payments for the entire Premises to an equivalent
net of electric basis Rent, at Tenant's sole cost for such sub-metering.
Equivalent electrical usage and payment shall separate the Tenant usage for
normal office use from the Common Area usage.  The Tenant would pay it's  direct
usage as determined by the electrical sub-meter with a credit for normal office
use against the Rent shown in Exhibit A-3, and a pro-rata allocation of the
Common Area utility costs;

          (iv) All maintenance, operation and service agreements for the
Building, the Land and the Common Area and any equipment related thereto,
including, without limitation, service and/or maintenance agreements for the
security, energy management, HVAC, plumbing and electrical systems, and for
window cleaning, elevator maintenance, janitorial service, groundskeeping,
interior and exterior landscaping and plant maintenance. Notwithstanding the
above, it shall be the Tenant's responsibility to maintain and repair all of its
above-standard electrical, HVAC and other improvements and equipment at its sole
cost;

          (v) All insurance purchased by Landlord or the Building's management
company relating to the Building, the Land and the Common Area and any equipment
or other property contained therein or located thereon including, without
limitation, casualty, liability, rental loss, sprinkler and water damage
insurance;

          (vi) All repairs to the Building and the Common Area, including
interior, exterior, structural or nonstructural repairs, and regardless of
whether foreseen or unforeseen including expenses to have the Building comply
with all applicable federal and local codes, (excluding only repairs paid for by
the proceeds of insurance or by Tenant or other third parties);

          (vii)     All maintenance of the Building, the Land and the Common
Area, including, without limitation, painting, ice and snow removal, window
washing, landscaping, groundskeeping, roof repair or replacement, relamping or
replacement of luminaries, HVAC repairs and maintenance to include replacement
of compressors, trash removal and the patching, painting and resurfacing of
roads, driveways and parking lots;

          (viii)    A management allowance for property management in an amount
not to exceed five percent (5%) of Basic and Additional Rent for space in the
Building payable to Landlord or the company or companies managing the Building,
the Land and the Common Area, if any;

          (ix) Accounting and legal fees incurred in connection with the
ownership, operation and maintenance of the Building, the Land and the Common
Area or related thereto;

          (x) Any additional services not provided to the Building, the Land or
the Common Area at the Commencement Date but thereafter provided by Landlord as
Landlord shall deem necessary or desirable in connection with the management or
operation of the Building, the Land and the Common Area;

          (xi) Any capital improvements made to the Building after the
Commencement Date (other than those made for the addition of rentable square
footage to the Building or for the sole benefit of a Building tenant pursuant to
its lease), the cost of which shall be amortized over such reasonable period as
Landlord shall determine, together with interest on the unamortized balance of
such cost at the Interest Rate or such higher rate as may have been paid by
Landlord on funds borrowed for the purposes of constructing said capital
improvements;

          (xii)     All Landlord's Taxes which are defined in Sections 6.3
below;

          (xiii) The costs incurred in implementing and operating any
transportation management program, ride sharing program or similar program
including, but not limited to, the cost of any transportation program fees, mass
transportation fees or similar fees charged or assessed required by any
governmental or quasi-governmental entity;

          (xiv)   The cost to operate the on-site recreational/exercise facility
on the Concourse Level.  For purpose of this Section 6.2, the operating cost of
this facility shall be a stipulated maximum of $25,000 for the Building in the
Base Year.

     Notwithstanding the above, Operating Expenses shall not include and Tenant
shall in no event have any obligation to perform or to pay for the following:

     (i) expenses for capital improvements made to the Demised Premises;

     (ii) Costs of repairs, restoration, replacements or other work occasioned
by fire, windstorm or other casualty of an insurable nature (whether such

                                       6
<PAGE>

destruction be total or partial) actually reimbursed to Landlord, the exercise
by governmental authorities of the right of eminent domain, whether such taking
exercise by governmental authorities of the right to eminent domain, whether
such taking be total or partial, or the negligence or intentional tort of
Landlord, or any subsidiary or affiliate of Landlord, or any representative,
employee or agent of same (including the costs of any deductibles paid by
Landlord);

     (iii) interest and amortization of funds borrowed by Landlord, whether
secured or unsecured, and other financing costs, except for maintenance and
repair;

     (iv) depreciation of the Building;

     (v) leasing commissions;

     (vi) costs, fines, interest, penalties, legal fees or costs of litigation
incurred due to the late payments of taxes, utility bills and other costs
incurred by Landlord's failure to make such payments when due;

     (vii) recovered costs for any items to the extent covered by a
manufacturer's materialmen's, vendor's or contractor's warranty (a "Warranty");

     (viii) income, excess profits, franchise taxes or other such taxes imposed
on or measured by the income of Landlord from the operation of the Demised
Premises, not including BPOL tax;

     (ix) costs of Landlord's defense of lawsuits against Landlord and any
judgments or costs of settlement;

     (x) legal fees and other costs (including prepayment of any indebtedness)
incurred in connection with any mortgaging, financing, refinancing, sale, charge
of ownership or entering into or extending or modifying any financing, ground
lease or any other lease or sublease to, or assumed by, directly or indirectly,
Landlord, Landlord's agents or Landlord's affiliates;

     (xi) accounting fees, other than those incurred in connection with the
preparation of statements required pursuant to the provisions of this Lease;

     (xii) costs and expenses (including court costs, attorneys' fees and
disbursements) related to or in connection with disputes with any holder of a
mortgage or by or among any persons having an interest in the Landlord or the
Demised Premises;

     (xiii) any cost incurred in connection with the investigation or
remediation of any Hazardous Materials located in, on, under or about the
Demised Premised as of the date of the Lease or any Hazardous Materials stored,
used or released by Landlord, its employees or agents after the date of the
Lease, and any cost incurred in connection with any government investigation,
order, proceeding or report with respect thereto.  As used herein, the term
"Hazardous Materials" includes any "hazardous substance" as that term is defined
in the Comprehensive Environmental Response, Compensation, and Liability Act (42
U.S.C. 9604 et seq.), as amended, and any "hazardous waste" as that term is
defined in the Resource Conservation and Recovery Act (42 U.S.C. 6901 et seq.,
as amended)(unless such substances were introduced in the Demised Premises by
Tenant, its invitees or guests);

     (xiv) costs incurred in connection with a sale, lease or transfer
(including testamentary transfers) of all or any part of the Demised Premises or
any interest therein, or of any interest in Landlord, or in any person
comprising, directly or indirectly, Landlord or in any person having an equity
interest, directly or indirectly in Landlord;

     (xv) any costs, fines or penalties incurred as a result of a violation by
Landlord of any legal requirements;

     (xvi) all costs and expenses (including services and utilities) payable
directly by Tenant;

     (xvii) all costs associated with the  initial construction of the Demised
Premises;

     (xviii) costs and expenses incurred by Landlord associated with the
operation of the business of the legal entity or entities which constitute
Landlord (as opposed to operation of the Building);

     (xix) charitable or political contributions;

           a.  costs occasioned by the act omission or violation of any Law by
Landlord or any other occupant of the Building or their respective agents
employees or contractors:

           b.  costs occasioned by casualty or condemnation:

                                       7
<PAGE>

           c. costs to correct any construction defect in the Premises or the
Building or to comply with any law applicable to the Premises or the Building on
the Commencement Date;

           d. costs of any renovation, improvement, painting or redecorating of
any tenant premise of the Building not made available for Tenant's use;

           e. costs incurred in connection with marketing or advertising the
Building, or the violation by Landlord or any occupant of the Building (other
than Tenant) of the terms and conditions of any lease or other agreement;

           f. insurance costs for coverage not customarily paid by tenants of
similar projects in the vicinity of the Premises, increases in insurance costs
caused by the activities of another occupant of the Building, insurance
deductibles in excess of $10,000, and co-insurance payments;

           g. costs incurred in connection with the presence of any hazardous
material, except to the extent caused by the release or emission of the
hazardous material in question by Tenant;

           h. costs in the nature of depreciation or other expense reserves;

           i. executives' salaries; and

           j. management fees in excess of five (5%) percent.

     6.3  Landlord's Taxes Defined.  "Landlord's Taxes" shall mean all taxes and
          -------------------------
assessments, including but not limited to, general or special, ordinary or
extraordinary, foreseen or unforeseen, assessed, levied or imposed by any
governmental authority upon the Building, the Land and the Common Area and upon
the fixtures, machinery, equipment or systems in, upon or used in connection
with any of the foregoing, and the rental, revenue or receipts derived
therefrom, under the current or any future taxation or assessment system or
modification of, supplement to, or substitute for such system.  Landlord's Taxes
also shall include special assessments which are in the nature of or in
substitution for real estate taxes, including, without limitation, road
improvement assessments, special use area assessments, school district
assessments, and transportation taxes, fees or assessments, including, but not
limited to, mass transportation fees, regional transportation district fees,
metrorail fees, trip fees and similar fees and assessments, fees assessed by any
air quality management district or other governmental or quasi-governmental
entity regulating pollution, parking fees or parking taxes paid by Landlord.  If
at any time the method of taxation prevailing at the Date of Lease shall be
altered so that in lieu of, as a substitute for or in addition to the whole or
any part of the taxes now levied or assessed, there shall be levied or assessed
a tax of whatever nature, then the same shall be included as Landlord's Taxes
hereunder.  Further, for the purposes of this Article, Landlord's Taxes shall
include the reasonable expenses (including, without limitation, attorneys' fees)
incurred by Landlord in challenging or obtaining or attempting to obtain a
reduction of such Landlord's Taxes, regardless of the outcome of such challenge.
Notwithstanding the foregoing, Landlord shall have no obligation to challenge
Landlord's Taxes.

     6.4  Estimated Payments.  Landlord shall submit to Tenant, before the
          -------------------
beginning of each calendar year, a statement of Landlord's reasonable estimate
of Landlord's Operating Expenses payable by Tenant during such calendar year.
In addition to the Basic Rent, Tenant shall pay to Landlord on or before the
first day of each month during such calendar year an amount equal to one-twelfth
(1/12) the estimated Landlord's Operating Expenses payable by Tenant for such
calendar year as set forth in Landlord's statement.  If Landlord fails to give
Tenant notice of its estimated payments due under this Section for any calendar
year, the Tenant shall continue making monthly estimated payments in accordance
with the estimate for the previous calendar year until a new estimate is
provided. If Landlord determines that, because of unexpected increases in
Landlord's Operating Expenses or other reasons, Landlord's estimate of
Landlord's Operating Expenses was too low, then Landlord shall have the right to
give a new statement of the estimated Landlord's Operating Expenses due from
Tenant for such calendar year or the balance thereof and to bill Tenant for any
deficiency which may have accrued during such calendar year, and Tenant shall
thereafter pay monthly estimated payments based on such new statement.

     6.5  Actual Landlord's Operating Expenses.  Within ninety (90) days after
          -------------------------------------
the end of each calendar year, Landlord shall submit a statement to Tenant
showing the actual Landlord's Operating Expenses for such calendar year and
Tenant's Proportionate Share of the amount by which such Landlord's Operating
Expenses exceed the Expense Stop.  If for any calendar year, Tenant's estimated
monthly payments exceed Tenant's Proportionate Share of the amount by which the
actual Landlord's Operating Expenses for such calendar year exceed the Expense
Stop, then Landlord shall give Tenant a credit in the amount of the overpayment
toward Tenant's next monthly payments of estimated Landlord's Operating Expenses
(or, in the last year of the Term, refund such overpayment directly to Tenant).

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<PAGE>

If for any calendar year Tenant's estimated monthly payments are less than
Tenant's Proportionate Share of the amount by which the actual Landlord's
Operating Expenses for such calendar year exceed the Expense Stop, then Tenant
shall pay the total amount of such deficiency to Landlord within thirty (30)
days after receipt of the statement from Landlord.  If Tenant fails to pay such
deficiency within thirty (30) days from receipt of the statement from Landlord,
Tenant shall pay Landlord a late charge of five percent (5%) of the amount of
such deficiency and any such deficiency shall bear interest, at the Interest
Rate, from the thirty-first (31st) day to the date of payment thereof by Tenant.
Landlord's and Tenant's obligations with respect to any overpayment or
underpayment of Landlord's Operating Expenses shall survive the expiration or
termination of this Lease.



     6.6  Allocation of Landlord's Operating Expenses to Tenant.  Landlord shall
          ------------------------------------------------------
equitably apportion to the extent possible the costs of utilities or services
which are provided to one tenant or tenants to an appreciably different degree
than to Building tenants at large.  In the event that Tenant shall request that
Landlord provide utilities or services other than, or in addition to, those
contemplated at the commencement of this Lease, as specified in Section 12.1
below.  Tenant agrees that Landlord may, by fifteen (15) days prior written
notice to Tenant, charge Tenant for the cost of such additional utility or
service as Additional Rent.

     6.7  Review Procedure.  If Tenant shall dispute any item or items included
          -----------------
by Landlord in determining Landlord's Operating Expenses or other Additional
Rent for any Lease Year, and if such dispute is not resolved between Landlord
and Tenant within sixty (60) days after such accounting has been rendered,
either party may notify the other of its election to arbitrate said dispute.  In
such event, such dispute shall be resolved by an independent certified public
accountant acceptable to Landlord and Tenant, which decision shall be conclusive
and binding on both parties and final judgment thereon may be entered in any
court of competent jurisdiction.

     6.8  Accounting Year.  Landlord may adopt a different accounting year than
          ----------------
the calendar year, in which case the times for payment of Additional Rent shall
be adjusted accordingly.

     6.9  Credit for Refunds.  In the event that, during or after the Term of
          -------------------
this Lease, Landlord shall receive a refund for any tax or other sum included in
the calculation of Landlord's Operating Expenses and paid by Tenant, Landlord
shall repay Tenant's Proportionate Share of such refund (after deducting
therefrom the cost and expense of obtaining such refund).

                                  ARTICLE VII

                                      USE

     7.1  General.  Tenant shall occupy the Premises solely for the Permitted
          --------
Use.  The Premises shall not be used for any other purpose without the prior
written consent of Landlord.  Tenant shall comply, at Tenant's expense, with (i)
all present and future laws, ordinances, regulations and orders of the United
States of America, the Commonwealth of Virginia and any other public or quasi-
public federal, state or local authority having jurisdiction over the Premises
with respect to Tenant's specific use of the Premises, and (ii) any reasonable
requests of Mortgagee or any insurance company providing coverage, with respect
to the Premises.  Tenant shall not use or occupy the Premises in any manner that
is unlawful or dangerous or that shall constitute waste, unreasonable annoyance
or a nuisance to Landlord or the other tenants of the Building.

     7.2  Hazardous Materials.  Tenant will not store, use or dispose of any
          --------------------
hazardous materials in, on or about the Premises, the Building or the Land.
Tenant shall not use the Premises for any use which may give rise to the
existence on the Premises, the Building or the Land of toxic materials,
hazardous substances or hazardous waste as those terms are used in the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980,
42 USC ss 9601 et seq, as amended, Superfund Amendments and Reauthorization Act
of 1986, Resource Conservation and Recover Act of 1976 or in any other Federal,
state or local law (and all regulations promulgated under any of same), as such
laws are amended from time to time.  Tenant will be solely responsible for and
will defend, indemnify and hold Landlord and its Agents harmless from and
against all claims, costs and liabilities, including attorney's fees and costs,
arising out of or in connection with Tenant's breach of its obligations under
this Section.  Tenant will be solely responsible for and will defend, indemnify
and hold Landlord and its Agents harmless from and against any and all claims,
costs, and liabilities, including attorney's fees and costs, arising out of or
in connection with the removal, clean-up and restoration work and materials
necessary to return the Premises and any other property of whatever nature
located on the Land to their condition existing prior to the appearance of
Tenant's hazardous materials on the Premises.  Tenant's obligations under this
Section will survive the expiration or earlier termination of this Lease.

                                       9
<PAGE>

     7.3  Hazardous Materials Representation.  To the best knowledge of
          -----------------------------------
Landlord, (a) no hazardous material is present in the Premises or in the
Building or the soil, surface water or groundwater thereof, (b) no underground
storage tanks are present on or about the Building, and (c) no action,
proceeding or claim is pending or threatened regarding the Building concerning
any hazardous material or pursuant to any environmental law.  Unless Tenant
introduces such hazardous material, Tenant shall not be liable for, and Landlord
shall indemnify, defend, protect and hold harmless Tenant, its agents,
contractors, stockholders, directors, successors, representatives and assigns
from and against, all losses, costs, claims, liabilities and damages (including
attorneys' and consultant's fees) of every type and nature, directly or
indirectly arising out of or in connection with any hazardous material present
at any time in, or about the Building, or the soil, air improvements,
groundwater or surface water thereof, or the violation of any environmental law,
except to the extent that any of the foregoing actually results from the release
or emission of hazardous material by Tenant or its agents, contractors,
stockholders, directors, successors, representatives or assigns.

                                  ARTICLE VIII

                                    PARKING

     8.1  Parking Spaces.  Tenant will have pro-rata use on a first-come, first-
          ---------------
served basis of the vehicular and bicycle parking spaces on the Land.  There
shall be no charge for parking during the initial Term of the Lease.

     8.2  Changes to Parking Facilities.  Landlord shall have the right, from
          ------------------------------
time to time, without Tenant's consent, to change, alter, add to, temporarily
close or otherwise affect the parking facilities on the Land in such manner as
Landlord, in its reasonable  discretion, deems appropriate including, without
limitation, the right to designate reserved spaces available only for use by one
or more tenants (however, in such event, those parking spaces shall still be
deemed Common Area for the purpose of the definition of Landlord's Operating
Expenses), provided that, except in emergency situations or situations beyond
Landlord's control, Landlord shall provide alternative parking facilities.

                                   ARTICLE IX

                                     SIGNS

     No sign, advertisement or notice shall be inscribed, painted, affixed,
placed or otherwise displayed by Tenant on any part of the Land or the outside
or the inside (including, without limitation, the windows) of the Building or
Premises.  In addition to suite signage provided by Landlord, Landlord shall
provide, at Landlord's expense, a listing on the Building directory of Tenant's
business name.  If any prohibited sign, advertisement or notice is nevertheless
exhibited by Tenant, Landlord shall have the right to remove the same, and
Tenant shall pay any and all expenses incurred by Landlord in such removal,
together with interest thereon at the Interest Rate, upon demand.  Landlord
shall have the right to prohibit any sign, advertisement, notice or statement to
the public by Tenant which, in Landlord's opinion, tends to impair the
reputation of the Building or its desirability as a first class office building.
Notwithstanding the above, Landlord will permit, at Tenant's sole cost and
expense, Building spandrel signage (i.e., on the spandrel between the Concourse
Level and First Floor) with Toll Road exposure and a place on the Building
monument sign at the specific entrance to the Building with Tenant's name or
logo on it.  Should tenant expand to lease 60,000 rentable square feet or more,
Tenant shall have the right, subject to availability , to Building exterior
signature signage with Toll Road visibility.

                                   ARTICLE X

                  INITIAL CONSTRUCTION; ALTERATIONS; SURRENDER

     10.1 Initial Construction.  Landlord and Tenant agree that the construction
          ---------------------
of the Tenant work and other initial construction with respect to the Premises
shall be performed in accordance with Exhibit B-1 attached hereto and made a
part hereof.  Tenant shall be solely responsible for all Initial Construction.

     10.2 Alterations.  (A)  For the purposes of this Section, "Alterations"
          ------------
shall mean any alterations, additions, decorations, or improvements to the
Premises or the Building.  Tenant shall have the right without Landlord's prior
consent to make Alterations to or upon the Premises which  i) are non-structural
in nature, ii) do not disrupt any other tenants of the Building, iii) do not
affect any Building systems, and iv) are not visible from outside the Premises;
provided, however, that Tenant must furnish Landlord with notice and detailed
plans and specifications of any such Alterations at least fifteen (15) days
prior to the commencement of such work.  Tenant shall not make or permit any
other  Alterations without the prior written consent of Landlord.  Regardless of
whether or not Landlord's consent is required to an Alteration, Landlord may
impose any reasonable conditions to the performance of the Alterations,
including without limitation, (i) delivery to Landlord of written and
unconditional waivers of mechanic's and materialmen's liens as to the Premises,
the Building and the Land for all work, labor and services to be performed and
materials to be furnished, signed by all contractors, subcontractors,
materialmen and laborers participating in the Alterations, (ii) prior approval

                                      10
<PAGE>

of the plans and specifications and Tenant's contractor(s) with respect to the
Alterations, (iii) supervision of the Alterations by Landlord's representative
at Tenant's expense and (iv) delivery to Landlord of payment and performance
bonds naming Landlord and Mortgagee as obligees.  All Alterations, whether or
not Landlord's consent is required, shall conform to the requirements of
Landlord's and Tenant's insurers and of the Federal, state and local governments
having jurisdiction over the Premises, shall be performed in accordance with the
terms and provisions of this Lease in a good and workmanlike manner befitting a
first class office building and shall not adversely affect the value, utility or
character of the Premises.  Should permits of any kind and nature be required by
Federal, state or local government(s)  having jurisdiction over the Premises,
Tenant shall be responsible for securing the permits and the cost of same and
furnishing copies of such permits to Landlord.

     (B)  If the Alterations are not performed as herein required, Landlord
shall have the right, at Landlord's option, to halt any further Alterations, or
to require Tenant to perform the Alterations as herein required or to require
Tenant to return the Premises to its condition before such Alterations.

     (C)  Within thirty (30) days of the completion of the Alterations, Tenant
shall furnish Landlord with one set of reproducible sepias showing the actual,
as-built Alterations as they were delivered in the Premises, certified and
inspected by the architects and engineers who prepared the plans and
specifications.

     (D)  Notwithstanding the foregoing, if any mechanic's or materialmen's lien
is filed against the Premises, the Building or the Land for work claimed to have
been done for, or materials claimed to have been furnished to or for the benefit
of, Tenant, such lien shall be discharged of record by Tenant within ten (10)
days by the payment thereof or the filing of any bond required by law.  If
Tenant shall fail to discharge any such lien, Landlord may (but shall not be
obligated) discharge the same, the cost of which shall be paid by Tenant within
three (3) days of demand by Landlord.  If Tenant fails to pay the cost within
five (5) days  of demand by Landlord, Tenant shall pay to Landlord a late charge
of five percent (5%) of the amount.  In addition, such late payment shall bear
interest, at the Interest Rate, from the fourth (4th) day to the date of payment
thereof by Tenant.  Such discharge by Landlord shall not be deemed to waive or
release the default of Tenant in not discharging the same.  Neither Landlord's
consent to any Alteration nor anything contained in this Lease shall be deemed
to be the agreement or consent of Landlord to subject Landlord's interest in the
Premises, the Building or the Land to any mechanic's or materialmen's liens
which may be filed in respect of any Alteration.

     10.3 Treatment of Alterations at Expiration Date or Earlier Termination of
          ---------------------------------------------------------------------
Lease. At the time Landlord approves an Alteration, Landlord shall notify Tenant
-----
of the extent of any Alterations which shall remain on the Premises, which
Alterations shall be surrendered at the end of the Lease Term as the property of
the Landlord. Landlord shall not waive any rights with respect to Alterations
made by Tenant and not known to Landlord two months before the end of the Lease
Term.

     Tenant shall have the obligation, with respect to other Alterations, to
restore the Premises to the condition existing prior to such Alterations, at
Tenant's expense, to include all necessary design and permit costs, using
licensed contractors acceptable to Landlord, unless this obligation was
affirmatively waived by Landlord in writing prior to the time such Alterations
were initially made.  Landlord shall have the option, with respect to such
Alterations, to be paid by Tenant the amount of money which would necessary to
have the Premises restored to a condition existing prior to such Alterations
using an outside licensed  third party contractor, to includeing supervisory,
design and permit costs.  In the latter circumstance, if Tenant fails to pay the
amount invoiced due within thirty (30) days from receipt of an itemized invoice
from Landlord, Tenant shall pay Landlord a late charge of five (5%) percent of
the amount invoiced for each month the payment is overdue, plus interest at the
Interest Rate from thirty (30) days after invoice submittal until date of
payment by Tenant, in addition to the sums described in the original invoice.

     10.4 Landlord Alterations.  Landlord shall have no obligation to make any
          ---------------------
Alterations in or to the Premises, the Building, the Common Area or the Land
except as specifically provided in Exhibit B-1.  Landlord hereby reserves the
right, from time to time, to make Alterations to the Building, change the
Building dimensions, erect additional stories thereon and attach other buildings
and structures thereto, and to erect such scaffolding and other aids to
construction as Landlord deems appropriate, and no such Alterations, changes,
construction or erection shall constitute an eviction, constructive or
otherwise, or permit Tenant any abatement of Rent or claim against Landlord.

     10.5  Low Voltage Cabling.  Low voltage cabling for control, alarms, phone,
           -------------------
data, and computer networking shall be installed in accordance with local codes
and the current version of the National Electrical Code.  All cabling shall be

                                      11
<PAGE>

hung off building structural elements via J-hooks or raceways accessible from
the underside.  If copper wiring is used for data communications or networking,
it shall be in accordance with the attached specifications (see Exhibit F).  To
the extent not superseded by the specifications of Exhibit F, the cable plant
shall conform to EIA/TIAA standards 568A, 569, 606, 607, and TSB 67,72 75 where
applicable.  Cabling penetrations between fire-rated areas shall be made with UL
rated fixtures incorporating removable sleeves to facilitate re-wiring.  Each
cable runout from a central distribution point to a wall socket shall be tested
to a 155 Mhz transmission rate, and copies of test reports for each run shall be
kept and supplied to Landlord upon request.  A current wiring map shall be
maintained for all low voltage cabling within the Premises and the terminations
of each cabling runs shall be identified by number both at the end of the wires
and on the socket plate within the wall, to enable rapid re-use of such cabling
by a successor tenant.  Network hubs and switches shall be considered personal
property of the Tenant, but all other cabling infrastructure shall either be
surrendered to the Landlord in good operating condition at Lease termination, or
at Landlord's option, removed at Tenant's expense.

       10.6  Surrender of the Premises.  Tenant shall peaceably surrender the
       --------------------------------
Premises, including any and all Leasehold Improvements  installed during the
Term regardless of whether Landlord or Tenant installed or paid for them, to
Landlord on the Expiration Date or earlier termination of this Lease, in broom-
clean condition and in as good condition as when Tenant took possession,
including, without limitation, the repair of any damage to the Premises caused
by the removal of any of Tenant's personal property from the Premises, except
for reasonable wear and tear and loss by fire or other casualty not caused by
Tenant or its Agents.  Any of Tenant's personal property left on or in the
Premises, the Building or the Common Area after the Expiration Date or earlier
termination of this Lease shall be deemed to be abandoned, and, at Landlord's
options, shall become property of title shall pass to Landlord under this Lease.
Notwithstanding the foregoing, Tenant shall be allowed to remove, at the end of
their Lease Term, and restore the Premises, Building and grounds, its UPS
system, generator, supplemental HVAC systems, audio visual and other electronic
equipment.

     10.7 Dispute Resolution.   Any dispute over the rights or obligations of
          ------------------
Landlord or Tenant with respect to issues covered by this Article X, either
party will have the right to invoke binding arbitration with respect to such
issues pursuant to the procedure set forth in Exhibit G.

                                   ARTICLE XI

                             MAINTENANCE AND REPAIR

     11.1 Landlord's Obligation.  As long as no Event of Default has occurred
          ----------------------
and is continuing, Landlord shall keep and maintain in good repair and working
order the Building, the Common Area, and the equipment within and serving the
Premises and the Building (excluding above-standard improvements installed or
paid for by Tenant) that are required for the normal maintenance and operation
of the Premises and the Building.  The cost of such maintenance and repairs to
the Building, the Common Area and said equipment shall be included in the
Landlord's Operating Expenses and paid by Tenant as provided in Article VI
herein. Tenant agrees to give Landlord prompt notice of any defective conditions
which come to its attention.  In addition, Tenant will benefit from all Year
2000 warranties/guarantees associated with the Base Building's systems.

     11.2 Tenant's Obligation.  Tenant shall maintain and repair any above-
          --------------------
standard equipment, fixtures or other improvements to the Premises and all
personal property within the Premises and shall repair, at its expense, any and
all damage caused by Tenant or Tenant's Agents to the Building, the Common Area,
or the Premises, including equipment within and serving the Building, ordinary
wear and tear excepted.  Notwithstanding the foregoing, Tenant shall bear the
cost of but shall not perform without Landlord's prior consent any repairs which
would affect the Building's structure or mechanical or electrical systems or
which would be visible from the exterior of the Building or any interior Common
Area of the Building.  In the event Landlord makes such repair or performs such
maintenance, Landlord may add the cost thereof to the first installment of Rent
which shall thereafter become due.

     11.3 Landlord's Right to Maintain or Repair.  If, within five (5) days
          ---------------------------------------
following notice to Tenant, Tenant fails to commence to repair or replace any
damage to the Premises or Building which is Tenant's obligation to perform, and
diligently pursue timely completion of such repair and replacement, Landlord
may, at its option, cause all required maintenance, repairs or replacements to
be made.  Tenant shall promptly pay Landlord all costs incurred in connection
therewith plus interest thereon at the Interest Rate from the due date until
paid.  In addition, where Tenant is prevented under Section 11.2 from performing
certain maintenance or repairs which are Tenant's obligation and Landlord
performs same, Tenant shall promptly pay to Landlord all costs incurred in
connection therewith plus interest thereon at the Interest Rate from the due
date until paid.

                                      12
<PAGE>

                                  ARTICLE XII

                        LANDLORD SERVICES AND UTILITIES

     12.1 Ordinary Services to the Premises.  As long as no Event of Default has
          ----------------------------------
occurred and is continuing, Landlord shall furnish to the Premises throughout
the Term (i) electricity, heating and air conditioning appropriate for the
Permitted Use during the normal business hours set forth in Exhibit C, except
for holidays set forth in Exhibit D; (ii) normal and customary janitorial and
char services as outlined in Exhibit E;  (iii) regular trash removal from the
Premises;  (iv) hot and cold water from points of supply;  (v)  restrooms as
required by applicable code; and (vi) elevator service; provided that Landlord
shall have the right to remove such elevators from service as may be required
for moving, freight or for servicing or maintaining the elevators or the
Building.  The cost of all services provided by Landlord hereunder shall be
included within Landlord's Operating Expenses, unless charged directly (and not
as or part of Landlord's Operating Expenses) to Tenant or another tenant of the
Building.

     12.2  After-Hours Services to the Premises.  If Tenant requires or requests
           -------------------------------------
that the services to be furnished by Landlord (except Building standard
electricity and elevator service) be provided during periods in addition to the
periods set forth in Section 12.1, then Tenant  shall pay upon demand Landlord's
additional expenses resulting therefrom.  Landlord may, from time to time during
the Term, set a per hour charge for after-hours service which shall include the
cost of the utility, service, labor costs, administrative costs and a cost for
depreciation of the equipment used to provide such after-hours service.  The
current cost is $45.00 per hour per unit.

     12.3  Interruption of Services.  Landlord shall not be liable for, nor
           -------------------------
shall there be any abatement of Rent or constructive eviction for, the failure
to furnish, or the delay or suspension in furnishing, any of the services either
ordinary or extraordinary required under this Article, whether caused by
breakdown, maintenance, repair, strikes, scarcity of labor or materials, acts of
God or any other cause whatsoever, unless due to the gross negligence or willful
misconduct of Landlord.

     12.4  Meters.  Landlord reserves the right to separately meter or monitor
           -------
the utility services provided to the Premises and bill the charges directly to
Tenant or to separately meter any other tenant and bill the charges directly to
such tenant and to make appropriate adjustments to the Expense Stop based on the
meter charges.  Tenant also shall have the right to arrange its own separately
metered service, all costs thereof to be paid for by Tenant.

     12.5  Utility Charges.  All telephone, electricity, gas, heat and other
           ----------------
utility service used by Tenant in the Premises shall be paid for by Tenant
except to the extent the cost of same is included within Landlord's Operating
Expenses.

                                  ARTICLE XIII

                             RULES AND REGULATIONS

     Tenant and its Agents shall at all times abide by and observe the rules and
regulations attached as Exhibit C and any amendments or supplements thereto (the
"Rules and Regulations") that may be promulgated from time to time by Landlord
for the operation and maintenance of the Building and the Common Area and the
Rules and Regulations shall be deemed to be covenants of the Lease to be
performed and/or observed by Tenant.  Nothing contained in this Lease shall be
construed to impose upon Landlord any duty or obligation to enforce the Rules
and Regulations, or the terms or provisions contained in any other lease,
against any other tenant of the Building. Landlord shall not be liable to Tenant
for any violation by any party of the Rules and Regulations or the terms of any
other building lease.  If there is any inconsistency between this Lease and the
Rules and Regulations, this Lease shall govern.  Landlord reserves the right to
amend and modify the Rules and Regulations as it deems necessary.

                                  ARTICLE XIV

                             LIABILITY OF LANDLORD

     14.1  No Liability.  Landlord and its Agents shall not be liable to Tenant
           -------------
or its Agents for, and Tenant, for itself and its Agents, does hereby release
Landlord and its Agents from liability for, any damage, compensation or claim

                                      13
<PAGE>

arising from (i) the necessity of repairing any portion of the Premises or the
Building or the Common Area or any structural defects thereto, (ii) any
interruption in the use of the Premises or the Common Area, (iii) fire or other
casualty or bodily, personal or property injury, damage or loss resulting from
the use or operation (by Landlord, Tenant, or any other person whomsoever) of
the Premises or the Building or the Common Area, (iv) the termination of this
Lease, (v) robbery, assault or theft, or (vi) any leakage in the Premises or the
Building from water, rain, snow or other cause whatsoever, unless, in any of the
foregoing instances, such claim arises from the gross negligence or willful
misconduct of Landlord or its Agents.  No such occurrence shall give rise to
diminution of Rent or constructive eviction.  Any goods, automobiles, property
or personal effects stored or placed by Tenant or its Agents in or about the
Premises, the Building or the Common Area shall be at the sole risk of Tenant,
and Landlord and its Agents shall not in any manner be held responsible
therefor.  Except to the extent expressly prohibited by law, Tenant hereby
waives any claim it might have against Landlord or its Agents for any
consequential damages sustained by Tenant arising out of the loss or damage to
any person or property of Tenant.

     14.2  Indemnity.  Tenant shall indemnify and hold Landlord and its Agents
           ----------
harmless from and against any and all damage, claim, liability, cost or expense
(including, without limitation, attorneys' or other professionals' fees) of
every kind and nature (including, without limitation, those arising from any
injury or damage to any person, property or business) incurred by or claimed
against Landlord or its Agents, directly or indirectly, as a result of, arising
from or in connection with Tenant's or its Agents' use and occupancy of the
Premises, the Building or the Common Area.

     14.3 Landlord Indemnity.  Landlord shall indemnify Tenant.  Notwithstanding
anything to the contrary in this Lease, Landlord shall not be released or
indemnified from, and shall indemnify, defend, protect and hold harmless Tenant
from, all losses, damages, liabilities, judgments, actions, claims, attorneys'
fees, consultants' fees, payments, costs and expenses arising from the gross
negligence or willful misconduct of Landlord or it agents, contractors,
representatives or invitees, Landlord's violation of any law, order or
regulation, or a breach of Landlord's obligations or representations under the
Lease.

                                   ARTICLE XV

                                   INSURANCE

     15.1 Insurance Rating.  Tenant shall not conduct or permit any activity, or
          -----------------
place any equipment or material, in or about the Premises, the Building or the
Common Area which will increase the rate of fire or other insurance on the
Building or insurance benefitting any other tenant of the Building; and if any
increase in the rate of insurance is stated by any insurance company or by the
applicable insurance rating bureau to be due to any activity, equipment or
material of Tenant in or about the Premises, the Building or the Common Area,
such statement shall be conclusive evidence that the increase in such rate is
due to the same and, as a result thereof, Tenant shall pay such increase to
Landlord upon demand.

     15.2  Liability Insurance.  Tenant shall, at its sole cost and expense,
           --------------------
procure and maintain throughout the Term a comprehensive general liability
policy insuring against claims, demands or actions arising out of or in
connection with: (i) the Premises; (ii) the condition of the Premises; (iii)
Tenant's operations in, maintenance and use of the Premises, Building and Common
Area, and (iv) Tenant's liability assumed under this Lease.  Such insurance
shall be in amounts not less than those approved by Landlord from time to time,
with an initial requirement of a combined single limit of not less than One
Million and No/100 Dollars ($1,000,000.00).  Such insurance shall also include
coverage against liability for bodily injuries or property damage arising out of
the use by or on behalf of Tenant by any owned, non-owned, or hired
transportation vehicles for a limit not less than that specified above.

     15.3  Personal Property/Improvements Insurance.  Tenant shall, at its sole
           -----------------------------------------
cost and expense, procure and maintain throughout the Term a property insurance
policy (written on an "All Risk" or "Special Causes of Loss" basis) insuring all
(One hundred (100%) percent) of Tenant's personal property, including but not
limited to equipment, furniture, fixtures, furnishings and leasehold
improvements installed at the Premises by Landlord or Tenant for not less than
the full replacement cost of said property.  All proceeds of such insurance
shall be used to repair or replace Tenant's property and improvements to the
Premises.

     15.4  Other Insurance.  Tenant shall, at all times during the Term hereof,
           ---------------
maintain in effect worker's compensation insurance as required by applicable law
and business interruption insurance reasonably satisfactory to Landlord.

     15.5  Requirements of Insurance Coverage.  All such insurance required to
           -----------------------------------
be carried by Tenant herein shall be with an insurance company licensed to do
business in the Commonwealth of Virginia and approved by Landlord. Such
insurance (i) shall contain an endorsement that such policy shall remain in full
force and effect notwithstanding that the insured has released its right of
action against any party before the occurrence of a loss; (ii) shall name

                                      14
<PAGE>

Landlord, and at Landlord's request, any mortgagee or ground lessor, as
additional insureds and loss payees as our interest may appear; (iii) shall
provide that the policy shall not be canceled, failed to be renewed or
materially amended without at least forty-five (45) days' prior written notice
(fifteen (15) days if due to non-payment of premium) to Landlord and, at
Landlord's request, any Mortgagee; and (iv) shall provide protection against any
peril included within the classification "All Risk" or "Special Causes of Loss",
including, but not limited to vandalism, malicious mischief, theft, sprinkler
leakage, earthquake and flood damage.  If this Lease is terminated as the result
of a casualty in accordance with Section XIX, the proceeds of said insurance
attributable to the replacement of all tenant improvements at the Premises shall
be paid to Landlord.  On or before the Commencement Date and, thereafter, not
less than thirty (30) days before the expiration date of the insurance policy,
an original of the policy (including any renewal or replacement policy) or a
certified copy thereof, together with evidence satisfactory to Landlord of the
payment of all premiums for such policy, shall be delivered to Landlord and, at
Landlord's request, to any Mortgagee.

     15.6  Waiver of Subrogation.  If either party hereto is paid any proceeds
           ----------------------
under any policy of insurance naming such party as an insured, on account of any
loss or damage, then such party hereby releases the other party hereto and all
other tenants, to and only to the extent of the amount of such proceeds, from
any and all liability for such loss or damage, notwithstanding that such loss,
damage or liability may arise out of the negligent or intentionally tortuous act
or omission of the other party or its Agents; provided, that such release shall
be effective only as to a loss or damage occurring while the appropriate policy
of insurance of the releasing party provides that such release shall not impair
the effectiveness of such policy or the insured's ability to recover thereunder.
Each party hereto shall use reasonable efforts to have a clause to such effect
included in any such policy.

     15.7  Security.  In the event that Landlord engages the services of a
           ---------
professional security system for the Building or adopts any policy to promote
security for the Building, it is understood that such engagement or policy shall
in no way increase Landlord's liability for occurrences and/or consequences
which such a system or policy is designed to detect or avert and that Tenant or
its Agents shall look solely to Tenant's insurer as set out above for claims for
damages or injury to any person or property.

     15.8 Landlord shall be required to maintain property insurance on Building
equal to full replacement value.

                                  ARTICLE XVI

                         RIGHT OF ENTRY AND IMPROVEMENT

     Except in the case of emergencies, Tenant shall permit Landlord or its
Agents, with 24 hour advance notice at any time and without notice, to enter the
Premises, without charge therefor to Landlord and without diminution of Rent,
(i) to examine, inspect and protect the Premises and the Building, (ii) to make
such alterations and repairs or performs such maintenance which in the sole
judgment of Landlord may be deemed necessary or desirable, (iii) to exhibit the
same to prospective purchasers of the Building or to present or future
Mortgagees or (iv) to exhibit the same to prospective tenants during the last
ten (10) months  of the Term and to erect on the Premises a suitable sign
indicating the Premises are available.  Should Tenant on its own volition vacate
the Premises or any portion thereof within six (6) months prior to the
expiration of the Term and not sublet such portion, Landlord or Landlord's Agent
shall have the right, without notice, to restore, refit or improve such vacated
portion of the Premises for a successor tenant, without affecting Tenant's
obligation to pay Rent under Article IV.

                                  ARTICLE XVII

                        TENANT'S EQUIPMENT AND PROPERTY

     17.1  Moving Tenant's Property.  Any and all damage or injury to the
           -------------------------
Premises or the Building caused by moving the property of Tenant into or out of
the Premises, or due to the same being on the Premises, shall be repaired by
Landlord, at the expense of Tenant.  No furniture, equipment or other bulky
matter of any description shall be received into the Building or carried in the
elevators except as may be approved in writing by Landlord, and the same shall
be delivered only through the designated delivery entrance and freight elevator
in the Building, at such times as shall be designated by Landlord.  All moving
of furniture, equipment, and other materials shall be under the direct control
and supervision of Landlord; provided, however, in no event shall Landlord be
responsible for any damages to or charges for moving the same.  Tenant shall
promptly remove from the Common Area any of Tenant's furniture, equipment or
other property there deposited.

                                      15
<PAGE>

     17.2  Installing and Operating Tenant's Equipment.  Except for Initial
           --------------------------------------------
Construction, without first obtaining the written consent of Landlord, Tenant
shall not install or operate in the Premises (i) any electrically operated
equipment or other machinery, other than standard office equipment that does not
require wiring, cooling or other service in excess of Building standards, (ii)
any equipment of any kind or nature whatsoever which will require any changes,
replacements or additions to, or changes in the use of, any water, heating,
plumbing, air conditioning or electrical system of the Premises or the Building,
or (iii) any equipment which places a load upon the framed floor of the Premises
exceeding an average rate of fifty (50) pounds live load per square foot of the
Premises.  Landlord's consent to such installation or operation may be
conditioned upon the payment by Tenant of additional compensation for any excess
consumption of utilities and any additional power, wiring, cooling or other
service (as determined in the reasonable  discretion of Landlord) that may
result from such equipment.  Machines and equipment which cause noise or
vibration that may be transmitted to the structure of the Building or to any
space therein so as to be objectionable to Landlord or any other Building tenant
shall be installed and maintained by Tenant, at its expense, on vibration
eliminators or other devices sufficient to eliminate such noise and vibration.

                                 ARTICLE XVIII

                           ASSIGNMENT AND SUBLETTING

     18.1  General.  Tenant shall not, without Landlord's prior written consent,
           --------
not to be unreasonably withheld, conditioned or delayed (i) assign this Lease
nor sublet the Premises in whole or in part, and shall not permit Tenant's
interest in the Lease to be vested in any third party by operation of law or
otherwise except as provided below.



     18.2  Landlord's Rights Upon Proposed Subletting.  Should Tenant desire to
           -------------------------------------------
sublet any part of the Premises, Tenant shall not be permitted so to sublet
until Tenant shall have given Landlord at least thirty (30) days  prior written
notice of Tenant's intention to offer such space for sublet and specifying the
terms of such sublet.  Landlord shall have the right for thirty (30) days   from
receipt of such notice to (i) sublet or (ii) take an assignment from Tenant,
upon the terms and for the period set forth in the notice.  In the event
Landlord exercises any right to sublease or take assignment of space from
Tenant, Landlord shall remit each month to Tenant rent in accordance with the
terms set forth in the aforesaid notice for the period of the sublease or
assignment.  In such event, Tenant shall not be responsible for any failure to
pay rent by the occupant of the portion of the Premises sublet or assigned to
the Landlord, and Tenant further shall not be responsible for other Tenant
obligations with respect to such portion of the Premises for the term of such
sublet or assignment.  Should Landlord not elect to accept assignment of such
space, Tenant may sublet the same only after obtaining the prior written consent
of Landlord, which consent shall not be unreasonably withheld, conditioned or
delayed.  Tenant agrees that disapproval of such sublet by Landlord's lender is
deemed a reasonable basis for withholding consent.

     18.3  Landlord's Right to Terminate.  Should Tenant desire to sublet more
           ------------------------------
than fifty (50%) percent  of the rentable space in the Premises, in the
aggregate, or if Tenant desires to assign this Lease in whole or in part, then
Landlord shall have the right, in addition to the foregoing, to terminate this
Lease by giving notice thereof to Tenant within thirty (30) days from the date
of Tenant's notice to Landlord and this Lease shall thereupon terminate on the
date specified in Landlord's notice but not earlier than thirty (30) days nor
later than the end of the next calendar month after the date of Landlord's
notice to Tenant exercising such right of termination.  Such termination shall
not be deemed a default by Tenant under this lease and Tenant shall be relieved
of all obligations under this Lease accruing after the date of such termination.
In this event, any Security Deposit then outstanding will be returned to Tenant.

     18.4  Conditions to a Sublease or Assignment by Tenant.  After receipt of
           -------------------------------------------------
Landlord's written consent, a duly executed copy of the sublease shall be
delivered to Landlord for Landlord's review and approval, which shall be given
within ten (10) business days of such delivery to Landlord.  All subleases shall
provide that the subtenant must comply with all applicable terms and conditions
of this Lease.  All assignments shall contain an assumption by the assignee of
all the terms and obligations of this Lease.  Should Landlord consent to the
proposed assignment or subletting, Tenant shall pay to Landlord, upon Tenant's
receipt thereof, one-half ( 1/2) of any amount of cash in excess of that which
would be received by Landlord for the sublet space, of rent or other sums
directly or indirectly received by Tenant from any subtenant or assignee
including any rent or other sums which may exceed the Basic Rent and Additional
Rent due hereunder after the provision of reasonable  costs and expenses in
connection with the sublet, such as tenant improvements and leasing commissions.
Tenant agrees that, notwithstanding any assignment or sublease, and
notwithstanding the acceptance of rent by the Landlord from an assignee,
sublessee, or any other part, the Tenant shall remain fully liable for the
payment of rent due and to become due under this Lease and for the performance

                                      16
<PAGE>

of all the covenants, agreements, terms, provisions, and conditions of this
Lease on the part of Tenant to be performed or observed.

     18.5  Additional Conditions.  Any transfer of this Lease from Tenant by
           ----------------------
merger, reorganization, liquidation, or the sale, conveyance, transfer by
bequest or inheritance, or other transfer of a controlling interest in Tenant
(whether by transfer of stock, partnership interests or otherwise) shall
constitute an assignment for the purposes of this Lease.  No assignment or
subletting shall be made to any person or entity for the conduct of a business
which is not in keeping with the requirements of the applicable zoning
regulations and standards and general character of the Building.  All Lease
Options associated with the Lease do not automatically convey with the
assignment or subletting of this Lease and specific approval must be requested
and obtained from Landlord.  Consent to a given assignment or sublease shall not
relieve Tenant or subtenant from its obligation to receive Landlord's written
consent to any subsequent assignment or sublease pursuant to the procedure of
this section.  Notwithstanding the above, occupancy by any affiliate or
subsidiary shall not be considered an assignment or sublease.

                                  ARTICLE XIX

                              DAMAGE; CONDEMNATION

     19.1  Damage to the Premises.  If the Premises shall be damaged by fire or
           -----------------------
other cause without the fault or negligence of Tenant or its Agents, Landlord
shall diligently and as soon as practicable after such damage occurs (taking
into account the time necessary to effect a satisfactory settlement with any
insurance company involved) repair such damage at the expense of Landlord;
provided, however, that Landlord's obligation to repair such damage shall not
exceed the proceeds of insurance available to Landlord (reduced by any proceeds
retained pursuant to the rights of Mortgagee).  Notwithstanding the foregoing,
if the Premises or the Building is damaged by fire or other cause to such an
extent that, in Landlord's sole judgment, the damage cannot be substantially
repaired within one hundred eighty (180) days after the date of such damage, or
if the Premises are damaged during the last  Lease Year , then Landlord or
Tenant within thirty (30) days from the date of such damage may terminate this
Lease by notice to the other.  If either Landlord or Tenant terminates this
Lease, the Rent shall be apportioned and paid to the date of such termination.
If neither Landlord nor Tenant so elects to terminate this Lease but the damage
required to be repaired by Landlord is not repaired within one hundred eighty
(180) days from the date of such damage (such one hundred eighty (180) day
period to be extended by the period of any delay outside the direct control of
Landlord plus a reasonable period for a satisfactory settlement with any
insurance company involved), Tenant, within thirty (30) days from the expiration
of such one hundred eighty (180) day period (as the same may be extended), may
terminate this Lease by notice to Landlord. During the period that Tenant is
deprived of the use of the damaged portion of the Premises, and provided such
damage is not the consequence of the fault or negligence of Tenant or its
Agents, Basic Rent and Tenant's Proportionate Share shall be reduced by the
ratio that the rentable square footage of the Premises damaged bears to the
total rentable square footage of the Premises before such damage.  All injury or
damage to the Premises or the Building resulting from the fault or negligence of
Tenant or its Agents shall be repaired by Tenant, at Tenant's expense, and Basic
Rent shall not abate.  If Tenant shall fail to do so or if Landlord shall so
elect, Landlord shall have the right to make such repairs, and any expense so
incurred by Landlord, together with interest thereon at the Interest Rate, shall
be paid by Tenant upon demand.  Notwithstanding anything herein to the contrary,
Landlord shall not be required to rebuild, replace or repair any above-standard
work or improvements or any other personal property of Tenant.

     19.2  Condemnation.  If more than fifty percent (50%) of the Premises or
           -------------
the Building shall be taken or condemned by any governmental or quasi-
governmental authority for any public or quasi-public use or purpose (including,
without limitation, sale under threat of such a taking), then the Term shall
cease and terminate as of the date when title vests in such governmental or
quasi-governmental authority, and Basic Rent shall be pro-rated to the date when
title vests in such governmental or quasi-governmental authority.  If fifty
percent (50%) or less of the Premises is taken or condemned by any governmental
or quasi-governmental authority for any public or quasi-public use or purpose
(including, without limitation, sale under threat of such a taking), Basic Rent
and Tenant's Proportionate Share shall be reduced by the ratio that the portion
so taken bears to the rentable square footage of the Premises before such
taking, effective as of the date when title vests in such governmental or quasi-
governmental authority, and this Lease shall otherwise continue in full force
and effect.  Tenant shall have no claim against Landlord (or otherwise) as a
result of such taking, and Tenant hereby agrees to make no claim against the
condemning authority for any portion of the amount that may be awarded as
compensation or damages as a result of such taking; provided, however, that
Tenant may, to the extent allowed by law, claim an award for moving expenses and
for the taking of any of Tenant's property (other than its leasehold interest in
the Premises) which does not, under the terms of this Lease, become the property
of Landlord at the termination hereof as long as such claim is separate and
distinct from any claim of Landlord and does not diminish Landlord's award.
Tenant hereby assigns to Landlord any right and interest it may have in any
award for its leasehold interest in the Premises.

                                      17
<PAGE>

                                  ARTICLE XX

                               DEFAULT OF TENANT

     20.1 Monetary Default.  The following events shall be deemed to be events
          ----------------
of monetary default by Tenant under this Lease.  Landlord shall notice Tenant of
such Monetary Default and Tenant shall have five (5) days from such notice to
cure.

     (A) Tenant shall fail to pay when due, any installment of Basic Rent,
         Additional Rent, Operating Expense, Real Estate Tax or any other
         payment or reimbursement to Landlord required herein when due and such
         failure shall continue for a period of five (5) business days from the
         date such payment was due;

     (B) Tenant shall become insolvent or shall make a transfer in fraud of
         creditors, or shall make an assignment for the benefit of creditors or
         shall transfer all or substantially all of its assets to another person
         or entity.

     (C) Tenant shall file a petition under any section or chapter of the United
         States Bankruptcy Code or under any similar law or statute of the
         United States or any state thereof, or an order for relief shall be
         entered against Tenant in any proceeding filed against Tenant
         thereunder, which is not discharged within thirty (30) days;

     (D) A receiver or trustee shall be appointed for all or substantially all
         the assets of Tenant;

     (E) Tenant shall generally not pay its debts as such debts become due;

     (F) Tenant shall vacate all or a substantial portion of the Premises and is
         not actively subleasing the vacant Premises, prior to four (4) months
         before the termination of the Lease Term, whether or not the Tenant is
         in default of the rental payments due under this Lease.

     20.2  Non-Monetary Default: The following events shall be deemed to be
           --------------------
events of non-monetary default by Tenant under this Lease.

     (A) Tenant shall fail to maintain any insurance required hereunder;

     (B) Tenant refuses to take possession of the Premises upon Substantial
         Completion of the Premises;

     (C) Tenant shall fail to comply with any term, provision or covenant of
         this Lease (other than the foregoing in this paragraph) and shall not
         cure such failure within fifteen (15) days after written notice thereof
         to Tenant or such longer period reasonably required if Tenant is
         diligently pursuing such cure.

     20.3 Remedies: Upon occurrence of any Event of Default that continues
          --------
beyond any applicable cure period, Landlord, without prejudice to any other
rights or remedies Landlord may have under this Lease or otherwise, shall have
the option to pursue any one, all or combination of the following remedies
without a notice or demand whatsoever.

     (A) Terminate this Lease by giving written notice to that effect to the
         Tenant, in which event Tenant shall immediately surrender the Premises
         to Landlord, and if Tenant fails to do so, Landlord may, without
         prejudice to any other remedy which it may have for possession or
         arrearage in rent, re-enter and take possession of the Premises and
         expel or remove Tenant and any other person who may be occupying such
         Premises or any part thereof, without being liable for prosecution or
         any other claim for damages. In the event Landlord elects to terminate
         this Lease by reason of an event of default, then not-withstanding such
         termination, Tenant shall be liable for and shall pay to Landlord, the
         sum of all rental and other indebtedness accrued to date of such
         termination, plus at its option, at any time, the Landlord may choose
         to accelerate the entire balance due under the remainder of the Lease
         and any other monies due under the Lease required to be paid by Tenant
         to Landlord until the Expiration Date of the Lease at the then present
         value of all rents and other amounts as may be due in the future, with
         the Interest Rate as the discount rate for such a present value
         calculation, and with a reduction to be given for the total amount
         actually recovered from any reletting, net of reasonable reletting
         expenses to include brokerage and management fees, which may be paid to
         an affiliate of Landlord, redecoration or rebuilding costs for tenant
         fit-out, legal costs of reletting, costs of removing or storing
         Tenant's or other occupant's property, and other expenses reasonably
         incurred in the business of leasing and preparing office space for
         occupancy;

     (B) Alter all locks and other security devises at the Premises without
         terminating this Lease;

                                       18
<PAGE>

     (C) Re-enter and take possession of the Premises by legal process or by
         expelling or removing Tenant and any other person who may be occupying
         such Premises or any part thereof, without being liable for prosecution
         or any claim for damages therefore; and relet the Premises and receive
         the rent therefore. No legal process, re-entry, re-letting or taking
         possession of the Premises by the Landlord shall be construed as an
         election on its part to terminate this Lease unless a written notice of
         such intention is given to the Tenant. In the event that Landlord
         elects to retake or repossess the Premises, the Tenant shall be liable
         for and shall pay to Landlord, all rental and other indebtedness
         accrued to date of such repossession, plus at its option, at any time,
         the Landlord may choose to either: (1) accelerate the entire balance
         due under the remainder of the Lease and any other monies due under the
         Lease required to be paid by Tenant to Landlord until the Expiration
         Date of the Lease, including those referred to in Section 20.2(A)
         above; or (2) seek payment from Tenant for the difference between all
         sums due to Landlord from Tenant under this Lease and the amount
         received by Landlord through re-letting the Premises; Landlord may
         choose suit under option (2) and later accelerate under option (1); and
         all reasonable expenses incurred by Landlord in enforcing or defending
         Landlord's rights or remedies including reasonable attorney's fees and
         fifteen percent (15%) interest per annum on all the sum owing by Tenant
         to Landlord.

     (D) In the event Landlord may elect to gain possession of the Premises by a
         legal proceeding, Tenant hereby specifically waives any statutory
         notice which may be required prior to such proceeding, and agrees that
         Landlord's execution of this Lease is, in part considered for this
         waiver;

     (E) Enter upon the Premises without being liable for prosecution or any
         claim for damages therefore, and do what ever Tenant is obligated to do
         under the terms of this Lease, and Tenant agrees to reimburse Landlord
         on demand for any expenses which Landlord may incur and thus effecting
         compliance with Tenant's obligations under this Lease, and Tenant
         further agrees that Landlord shall not be liable for any damages
         resulting to the Tenant from such action, whether caused by the
         negligence of Landlord or otherwise;

     (F) In the event of termination or repossession of the Premises for an
         event of default, Landlord shall not have any obligation to relet or
         attempt to relet the Premises or any portion thereof, or to collect
         rental after re-letting, and in the event of reletting, Landlord may
         reject the whole or any portion of the Premises for any period to any
         tenant and for any use and purpose;

     (G) Landlord shall have a lien upon all the personal property of Tenant
         located in the Premises, as and for security for the rent and other
         obligations of Tenant herein provided. In order to perfect and enforce
         said lien, Landlord may at any time after default in the payment of
         rent or default of other obligations, seize and take possession of any
         and all personal property belonging to Tenant which may be found in and
         upon the Premises. If Tenant fails to redeem the personal property so
         seized, by payment of whatever sum may be due Landlord under and by
         virtue of the provisions of this lease, then and in that event,
         Landlord shall have the right, after twenty (20) days written notice to
         Tenant of its intention to do so, to sell such personal property so
         seized at public or private sale and upon such terms and conditions as
         to Landlord may appear advantageous, and after the payment of all
         proper charges incident to such sale, apply the proceeds thereof to the
         payment of any balance due to Landlord on account of rent or other
         obligations of Tenant pursuant to this Lease. In the event there shall
         then remain in the hands of Landlord any balance realized from the sale
         of said personal property as aforesaid, the same shall be paid over to
         Tenant. The exercise of the foregoing remedy by Landlord shall not
         relieve or discharge Tenant from any deficiency owed to Landlord which
         Landlord has the right to enforce pursuant to any other provision of
         this Lease.

     (H) Landlord, at its option, may bring a legal proceeding to recover from
         Tenant any monies owed under this Lease without seeking possession of
         the Premises. Such proceeding shall not be considered a termination of
         the Lease and Landlord shall retain the right to seek continuing rents
         as well as the right to accelerate all monies as provided in Section
         20.3(A) above owed for the full term of the Lease in subsequent legal
         proceedings. In the event of a default under 20.2(C) that remains
         uncured after fifteen (15) days from Date of Notice,

                                       19
<PAGE>

         and Landlord does not elect to accelerate monies due under the Lease,
         Tenant shall pay 110% of the sum of Basic Rent, Additional Rent,
         Landlord's Operating Expenses, real estate tax or any other payment or
         reimbursement to Landlord required herein, during the period from
         expiration of the fifteen (15) day cure period until the date of actual
         cure.

     (I) Exercise by Landlord of any one or more remedies hereunder granted or
         otherwise available shall not be deemed to be a termination of this
         Lease or an acceptance of surrender of the Premises by Tenant, being
         understood that such termination or surrender can be effected only by
         written notice from Landlord specifying such termination.

     (J) The Tenant acknowledges that all accounts are due and payable as
         required in the Lease, and in the event Tenant fails to pay any
         installment of rent hereunder as and when such installment is due,
         Tenant shall pay to Landlord a late charge in an amount equal to five
         percent (5%) of such installment, and the failure to pay such amount
         shall be an event of default hereunder. In addition, a finance charge
         at a rate of fifteen percent (15%) per annum shall be charged on all
         accounts more than five (5) days past due. Interest will be charged
         back to the account due date and apply to all charges due from the
         Tenant including but not limited to minimum rent, percent rent, taxes,
         insurance and common area maintenance charges. The provision for such
         late charges and finance charges shall be in addition to all of
         Landlord's other rights and remedies hereunder or at law and shall not
         be construed as a penalty, liquidated damages or as limiting Landlord's
         remedies in any manner.


                                  ARTICLE XXI

                                    REPORTS

     21.1  Lease Anniversary Report. Tenant shall submit to Landlord, at each
           -------------------------
anniversary of the Lease Commencement Date, a financial statement consisting of
an income summary and balance sheet dated not later than six months prior to
submission, prepared by an accountant and certified by Tenant to be accurate.
Such information shall also be provided for and certified by any Guarantor under
the Lease. Failure to furnish such statement within fifteen (15) days of notice
by Landlord shall constitute an additional Event of Default for the Landlord may
apply the remedies of Section 20.2 above.

     21.2  Event of Default Report.  If Tenant is in default at any time during
           ------------------------
the Lease, for any cause listed in Section 20.1 above, in addition to being
liable for a late penalty fee and interest as stated in Section 4.4, Tenant
shall have the obligation of furnishing to Landlord, within fifteen (15) days of
the date Tenant comes into default, the most recently available income statement
and balance sheet, certified by Tenant as to their accuracy, and Landlord
covenants to protect the confidentiality thereof.

                                 ARTICLE XXII

                                   MORTGAGES

     22.1  Subordination.  This Lease is subject and subordinate to all ground
           --------------
or underlying leases and to any first Mortgage(s) which may now or hereafter
affect such leases, the Building, or the subordination shall be self-operative;
however, in confirmation thereof, Tenant shall execute promptly any instrument
that Landlord or any first Mortgagee may request confirming such subordination.
Tenant hereby constitutes and appoints Landlord as Tenant's attorney-in-fact to
execute any such instrument on behalf of Tenant.  Notwithstanding the foregoing,
before any foreclosure sale under a Mortgage, if the Mortgagee so elects, after
foreclosure, this Lease may continue in full force and effect and Tenant shall
attorn to and recognize as its landlord the purchaser of Landlord's interest
under this Lease.  Tenant shall, upon the request of a Mortgagee or Purchaser at
foreclosure, execute and delivery any instrument that has for its purpose and
effect the subordination of this Lease to the lien of any Mortgage, or Tenant's
attornment to such Purchaser.

     22.2  Mortgagee Protection.  Tenant agrees to give any Mortgagee by
           ---------------------
certified mail, return receipt

                                       20
<PAGE>

requested, a copy of any notice of default served upon Landlord, provided that
before such notice Tenant has been notified in writing of the address of such
Mortgagee. Tenant further agrees that if Landlord shall have failed to cure such
default within the time provided for in this Lease, then Mortgagee shall have an
additional thirty (30) days within which to cure such default; provided,
however, that if such default cannot be reasonably cured within that time, then
such Mortgagee shall have such additional time as may be necessary to cure such
default (including, without limitation, the commencement of foreclosure
proceedings, if necessary), in which event this Lease shall not be terminated or
Basic Rent abated while such remedies are being so diligently pursued. In the
event of the sale of the Land or the Building, by foreclosure or deed in lieu
thereof, the Mortgagee or purchaser at such sale shall be responsible for the
return of the Security Deposit only to the extent that such Mortgagee or
purchaser actually received the Security Deposit.

     22.3  Modification Due to Financing.  If, in connection with obtaining
           ------------------------------
construction or permanent financing for the Premises, the Building or the Land,
any lender (or Mortgagee) shall request reasonable modifications of this Lease
as a condition to such financing, Tenant shall promptly execute a modification
of this Lease, provided such modifications do not materially increase the
financial obligations of Tenant hereunder or materially adversely affect the
leasehold interest hereby created or Tenant's reasonable use and quiet enjoyment
of the Premises.  Tenant and Guarantor shall each, prior to execution and
throughout the Term, upon request from time to time, provide such financial
information and documentation about itself to Landlord or Mortgagee as may be
requested.

     22.4  Condition Precedent.  Landlord's obligation to perform its covenants
           --------------------
and agreements hereunder is subject to the condition precedent that this Lease
be approved by Mortgagee or the issuer of any commitment to make a construction
or mortgage loan.  Unless Landlord gives Tenant written notice within twenty
(20) days thirty (30) days forty-five (45) days after the date hereof that the
Mortgagee or issuer, or both, disapproves this Lease, then this condition shall
be deemed to have been satisfied or waived and the provisions of this Section
22.4 shall be of no further force or effect .

     22.5  Assignment for Financing Purposes.  If, at any time or times,
           ----------------------------------
Landlord assigns this Lease or the Basic Rent payable hereunder to the
Mortgagee, or to any other party for the purpose of securing financing (the
Mortgagee and any other such party are referred to herein as the "Financing
Party"), whether such assignment is conditional in nature or otherwise, the
following provisions shall apply:


          (i)  Such assignments to the Financing Party shall not be deemed an
assumption by the Financing Party of any obligations of Landlord hereunder
unless such Financing Party shall, by written notice to Tenant, specifically
otherwise elect;

          (ii) To the extent the Financing Party has assumed obligations under
(i) above, the Financing Party shall be treated as having assumed such
obligations only upon foreclosure of its Mortgage (or voluntary conveyance by
deed in lieu thereof) but before the Financing Party conveys the Land, Building
or Premises to another party.

     Tenant hereby agrees to enter into such agreement or instruments as may,
from time to time, be reasonably requested in confirmation of the foregoing.

                                 ARTICLE XXIII

                                 HOLDING OVER

     In the event that Tenant shall not immediately surrender the Premises to
Landlord on the Expiration Date or earlier termination of this Lease, Tenant
shall be deemed to be a tenant-at-will upon all of the terms and provisions of
this Lease, except the monthly Basic Rent shall be one hundred and fifty percent
(150%) of twice the monthly Basic Rent in effect during the last month of the
Term. Notwithstanding the foregoing, if Tenant shall hold over after the
Expiration Date or earlier termination of this Lease, and Landlord shall desire
to regain possession of the Premises, then Landlord may forthwith re-enter and
take possession of the Premises without process, or by any legal process in
force in the Commonwealth of Virginia. Tenant shall indemnify Landlord against
all liabilities and damages sustained by Landlord by reason of such retention of
possession.


                                 ARTICLE XXIV

                                QUIET ENJOYMENT

     Landlord covenants that if Tenant shall pay Basic Rent and perform all of
the terms and conditions of this Lease to be performed by Tenant, and if Tenant
shall not be in default of any provision in this Lease, then Tenant shall
peaceably and quietly occupy and enjoy possession of the Premises during the
Term

                                       21
<PAGE>

without molestation or hindrance by Landlord or any party claiming through or
under Landlord, subject to the provisions of this Lease and of any Mortgage to
which this Lease is subordinate and easements, conditions and restrictions of
record affecting the Land.


                                  ARTICLE XXV

                                 MISCELLANEOUS

     25.1  No Representations by Landlord.  Tenant acknowledges that neither
           -------------------------------
Landlord nor its Agents nor any broker has made any representation or promise
with respect to the Premises, the Building, the Land or the Common Area, except
as herein expressly set forth, and no rights, privileges, easements or licenses
are required by Tenant except as herein expressly set forth.  Tenant, by taking
possession of the Premises shall accept the Premises and the Building "AS IS,"
and such taking of possession shall be conclusive evidence that the Premises and
the Building are in good and satisfactory condition at the time of such taking
of possession.

     Notwithstanding the foregoing, Tenant's acceptance of the Premises shall
not be deemed a waiver of Tenant's rights herein to have defects in the Building
corrected at no cost to Tenant.  Tenant shall give  notice to Landlord whenever
Tenant becomes aware of such a defect, and Landlord shall correct such defect as
soon as practicable at Landlord's sole cost and expense.  Landlord represents
and warrants to Tenant that as of the Commencement Date: (i) the Building will
comply with all federal, state and local laws, ordinances, regulations and
requirements and shall be in good condition and repair, (ii) the electrical,
mechanical, HVAC, plumbing, sewer, elevator and other systems serving the
Building will be in good operating condition and repair, and (iii) the roof of
the Building will be in good condition, water tight and free of leaks.  Landlord
shall, promptly after receipt of knowledge of a breach of this warranty (from
Tenant) remedy any breach of the foregoing warranty at Landlord's sole cost and
expense.





     25.2  No Partnership.  Nothing contained in this Lease shall be deemed or
           ---------------
construed to create a partnership or joint venture of or between Landlord and
Tenant, or to create any other relationship between Landlord and Tenant other
than that of landlord and tenant.

     25.3  Brokers.  Landlord recognizes Broker(s) as the sole broker(s)
           --------
procuring this Lease and shall pay Broker(s) a commission therefor pursuant to a
separate agreement between Broker(s) and Landlord.  Landlord and Tenant each
represents and warrants to the other that it has not employed any broker, agent
or finder other than Broker(s) relating to this Lease.  Landlord shall indemnify
and hold Tenant harmless, and Tenant shall indemnify and hold Landlord harmless,
from and against any claim for brokerage or other commission arising from or out
of any breach of the indemnitor's representation and warranty.

     25.4  Estoppel Certificate.  Tenant shall, without charge, at any time and
           ---------------------
from time to time, but no more than twice in any twelve (12) month period,
within fifteen (15)  business days after request therefor by Landlord,
Mortgagee, any purchaser of the Land or the Building or any other interested
person, execute, acknowledge and deliver to such requesting party a written
estoppel certificate certifying, as of the date of such estoppel certificate,
the following: (i) that this Lease is unmodified and in full force and effect
(or if modified, that the Lease is in full force and effect as modified and
setting forth such modifications); (ii) that the Term has commenced (and setting
forth the Commencement Date and Expiration Date); (iii) that Tenant is presently
occupying the Premises; (iv) the amounts of Basic Rent and Additional Rent
currently due and payable by Tenant; (v) that any Alterations required by the
Lease to have been made by Landlord have been made to the satisfaction of
Tenant; (vi) to Tenant's knowledge that there are no existing set-offs, charges,
liens, claims or defenses against the enforcement of any right hereunder,
including, without limitation, Basic Rent or Additional Rent (or if alleged,
specifying the same in detail); (vii) that no Basic Rent (except the first
installment thereof) has been paid more than thirty (30) days in advance of its
due date; (viii) that Tenant has no knowledge of any then uncured default by
Landlord of its obligations under this Lease (or, if Tenant has such knowledge,
specifying the same in detail); (ix) that Tenant is not in default; (x) that the
address to which notices to Tenant should be sent is as set forth in the Lease
(or, if not, specifying the correct address); and (xi) any other certifications
reasonably requested by Landlord.  In addition, within ten (10)  days after
request by Landlord, but in no event more than twice in any twelve (12) month
period, Tenant shall deliver to Landlord audited financial statements of

                                       22
<PAGE>

Tenant for its most recently ended fiscal year and interim unaudited financial
statements for its most recently ended quarter, if such information is not
available in publically accessible form, and Landlord will protect the
confidentiality of such information.

     25.5  Waiver of Jury Trial.  Tenant and Landlord hereby waive trial by jury
           ---------------------
in any action, proceeding or counterclaim brought by Landlord against Tenant
with respect to any matter whatsoever arising out of or in any way connected
with this Lease, the relationship of Landlord and Tenant hereunder or Tenant's
use or occupancy of the Premises.  In the event Landlord commences any
proceedings for nonpayment of Rent, Tenant shall not interpose any
counterclaims.  This shall not, however, be construed as a waiver of Tenant's
right to assert such claims in any separate action brought by Tenant.

     25.6  Notices.  All notices or other communications hereunder shall be in
           --------
writing and shall be deemed duly given if delivered in person or upon the
earlier of receipt, if mailed by certified or registered mail, or three (3) days
after certified or registered mailing, return receipt requested, postage
prepaid, addressed and sent, if to Landlord to Landlord's Address specified in
Section 1.2; or if to Tenant to Tenant's Address specified in Section 1.6.
Landlord and Tenant may from time to time by written notice to the other
designate another address for receipt of future notices.

     25.7  Invalidity of Particular Provisions.  If any provisions of this Lease
           ------------------------------------
or the application thereof to any person or circumstances shall to any extent be
invalid or unenforceable, the remainder of this Lease, or the application of
such provision to persons or circumstances other than those to which it is
invalid or unenforceable, shall not be affected thereby, and each provision of
this Lease shall be valid and be enforced to the full extent permitted by law.

     25.8  Gender and Number.  All terms and words used in this Lease,
           ------------------
regardless of the number or gender in which they are used, shall be deemed to
include any other number or gender as the context may require.

     25.9  Benefit and Burden.  Subject to the provisions of Article XVIII and
           -------------------
except as otherwise expressly provided, the provisions of this Lease shall be
binding upon, and shall inure to the benefit of, the parties hereto and each of
their respective representatives, heirs, successors and assigns.  Landlord may
freely and fully assign its interest hereunder.



     25.10  Entire Agreement.  This Lease (which includes the Exhibits attached
            -----------------
hereto) contains and embodies the entire agreement of the parties hereto, and no
representations, inducements or agreements, oral or otherwise, between the
parties not contained in this Lease shall be of any force or effect.  This Lease
(other than the Rules and Regulations, which may be changed from time to time as
provided herein) may not be modified, changed or terminated in whole or in part
in any manner other than by an agreement in writing duly signed by Landlord and
Tenant.

     25.11 Authority.
           ----------

          (i) If Landlord or Tenant signs as a corporation, the person executing
this Lease on behalf of Tenant hereby represents and warrants that Tenant is a
duly formed and validly existing corporation, in good standing, qualified to do
business in the Commonwealth of Virginia, that the corporation has full power
and authority to enter into this Lease and that he or she is authorized to
execute this Lease on behalf of the corporation.  Tenant shall deliver to
Landlord upon demand evidence of such authority satisfactory to Landlord.

          (ii) If Landlord or Tenant signs as a partnership, the person
executing this Lease on behalf of Tenant hereby represents and warrants that
Tenant is a duly formed and validly existing partnership, in good standing,
qualified to do business in the Commonwealth of Virginia, that the partnership
has full power and authority to enter into this Lease and that he or she is
authorized to execute this Lease on behalf of the partnership.  Tenant shall
deliver to Landlord upon demand evidence of such authority satisfactory to
Landlord.

     25.12 Compliance Costs.  In the event any legal action is undertaken by
           -----------------
Landlord as a result of the failure of Tenant to comply with any term of this
Lease,  Tenant shall pay to Landlord, in addition to any other relief which may
be granted, Landlord's  reasonable costs of litigation, including, but not
limited to attorney's fees, travel costs, expert witnesses, discovery and court
costs, and other expenses necessitated by the litigation.  If the parties cannot
agree upon the amount of such costs, they shall request the court to determine
the proper amount.

                                       23
<PAGE>

     25.13  Interpretation.  This Lease is governed by the laws of the
            ---------------
Commonwealth of Virginia.

     25.14  Landlord's Consent.  Wherever and whenever in this Lease Landlord's
            -------------------
consent or agreement is required, unless otherwise provided, Landlord will not
unreasonably withhold, condition or delay its consent.

     25.15  No Personal Liability; Sale.  Neither Landlord nor its Agents,
            ----------------------------
whether disclosed or undisclosed, shall have any personal liability under any
provision of this Lease.  If Landlord defaults in the performance of any of its
obligations hereunder or otherwise, Tenant shall look solely to Landlord's
equity, interest and rights in the Building and Land for satisfaction of
Tenant's remedies on account thereof.  In the event that the original Landlord
hereunder, or any successor owner of the Building shall sell or convey the
Building, all liabilities and obligations on the part of the original Landlord,
or such successor owner, under this Lease occurring thereafter shall terminate
as of the day of such sale, and thereupon all such liabilities and obligations
shall be binding on the new owner.  Tenant agrees to attorn to such new owner.
Any successor to Landlord's interest shall not be bound by (i) any payment of
Basic Rent or Additional Rent for more than one (1) month in advance, except for
the payment of the first installment of Basic Rent for the initial Lease Year or
(ii) as to any Mortgagee or any purchaser at foreclosure, any amendment or
modification of this Lease made without the consent of such Mortgagee.

     25.16  Time is of the Essence.  Time is of the essence as to Tenant's and
            -----------------------
Landlord's obligations contained in this Lease.

     25.17  Force Majeure.  Landlord shall not be required to perform any of its
            --------------
obligations under this Lease, nor shall Landlord be liable for loss or damage
for failure to do so, nor shall Tenant thereby be released from any of its
obligations under this Lease, where such failure arises from or through acts of
God, strikes, lockouts, labor difficulties, explosions, sabotage, accidents,
riots, civil commotions, acts of war, results of any warfare conditions in this
or any foreign country, fire or casualty, government action or inaction, legal
requirements, energy shortage or any other causes whatsoever, unless such loss
or damage results from the willful misconduct or gross negligence of Landlord.

     25.18  Headings.  Captions and headings are for convenience of reference
            ---------
only.

     25.19 Memorandum of Lease.  Tenant shall, at the request of Landlord,
           --------------------
execute and deliver a memorandum of lease in recordable form.  Tenant shall not
record such a memorandum or this Lease without Landlord's consent. The party
requesting recordation of a memorandum of this Lease shall be obligated to pay
all costs, fees and taxes, if any, associated with such recordation.



     25.20

     25.21  Attorney-in-Fact.  If Tenant fails or refuses to execute and deliver
            -----------------
any instrument or certificate required to be delivered by Tenant hereunder
(including, without limitation, any instrument or certificate required under
Article XXI or Section 25.4 hereof) within fifteen (15) days, then Tenant
stipulates that if Tenant is notified in writing and fails to respond in such
fifteen (15) days time-frame then such request shall be deemed to be approved
and such documents as may have been required shall be deemed to have been
approved.

     25.22  Effectiveness.  The furnishing of the form of this Lease shall not
            --------------
constitute an offer and this Lease shall become effective upon and only upon its
execution by and delivery to each party hereto.

     25.23  Bankruptcy.  if the Tenant shall (i) make an assignment for the
            -----------
benefit of creditors, (ii) be unable to pay its debts as they become due in the
normal course, (iii) or acquiesce in a petition in any court (whether or not
pursuant to any statute of the United States or of any state) in any bankruptcy,
reorganization, composition, extension, arrangement or insolvency proceedings,
or (iv) make an application in any such proceedings for, or acquiesce in, the
appointment of a trustee or receiver for it, over all or any

                                       24
<PAGE>

portion of its property, or (v) if any petition shall be filed against Tenant in
any court (whether or not pursuant to any statute of the United States or of any
state) in bankruptcy, reorganization, composition, extension, arrangement or
insolvency proceedings, and (i) Tenant shall thereafter be adjudicated a
bankrupt or insolvent, or (ii) such petition shall be approved by any such
court, or (iii) such proceedings shall not be dismissed, discontinued or vacated
within thirty (30) days after such petition is filed; then, in any of said
events, this Lease shall immediately cease and terminate, at the option of the
Landlord, with the same force and effect as though the date of occurrence of
said event was the day fixed herein for expiration of the term of this Lease.

     25.24  Prohibition Against Recording.  Neither this Lease, nor any
            ------------------------------
memorandum, affidavit or other writing with respect thereto, shall be recorded
by Tenant or by anyone acting through, under or on behalf of Tenant.  Landlord
shall have the right to record a memorandum of this Lease, and Tenant shall
execute, acknowledge and deliver to Landlord for recording any memorandum
prepared by Landlord.

     25.25  Easements.  Landlord reserves to itself the right, from time to
            ----------
time, to grant such easements, rights and dedications that Landlord deems
necessary or desirable, and to cause the recordation of parcel maps and
restrictions, so long as such easements, rights dedications, maps and
restrictions do not unreasonably interfere with the use of the Premises by
Tenant.  Tenant shall sign any of the aforementioned documents within ten (10)
days after Landlord's request and Tenant's failure to do so shall constitute a
material default by Tenant.  The obstruction of Tenant's view, air, or light by
any structure erected in the vicinity of the project, whether by Landlord or
third parties, shall in no way affect this Lease or impose any liability upon
Landlord.

     25.26 Transportation Management.  Tenant shall fully comply with all
           --------------------------
future programs implemented or required by any governmental or quasi-
governmental entity or Landlord to manage parking, transportation, air
pollution, or traffic in and around the project or the metropolitan area in
which the project is located.

     25.27  Security Measures.  Tenant hereby acknowledges that Landlord shall
            ------------------
have no obligation whatsoever to provide guard service or other security
measures for the benefit of the Premises or the project, and Landlord shall have
no liability to Tenant due to its failure to provide such services.  Tenant
assumes all responsibility for the protection of Tenant, its agents, employees,
contractors and invitees and the property of Tenant and of Tenant's agents,
employees, contractors and invitees from acts of third parties.  Nothing herein
contained shall prevent Landlord, at Landlord's sole option, from implementing
security measures for the project or any part thereof, in which event Tenant
shall participate in such security measures and the cost thereof shall be
included within the definition of Landlord's Operating Expenses.  Landlord shall
have the right, but not the obligation, to require all persons entering or
leaving the project to identify themselves to a security guard and to reasonably
establish that such person should be permitted access to the project.

                                       25
<PAGE>

     IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease under seal
as of the Date of Lease.



ATTEST/WITNESS:                          LANDLORD: Parkridge Five Associates
                                                     Limited Partnership



__________________________________       By:_________________________[SEAL]

Name:_____________________________       Name: Sunrise Valley, Inc.

Title:____________________________       Title: General Partner
                                                Christopher W. Walker, President

                                         Date:_____________________


ATTEST/WITNESS:                          TENANT: Musicmaker.com, Inc.


__________________________________       By:_________________________[SEAL]

Name:_____________________________       Name: Mark Fowler

Title:____________________________       Title: Director of Finance
                                                and Administration


                                         Date:_____________________


STATE OF VIRGINIA
COUNTY OF FAIRFAX

I, the undersigned, Notary Public in and for the jurisdiction aforesaid do
hereby certify that CHRISTOPHER W. WALKER, President, Sunrise Valley, Inc., the
General Partner of Parkridge Five Associates Limited Partnership, a Virginia
Limited partnership, whose signature is signed to the foregoing Deed of Lease,
personally appeared before me this _____ day of September1999, and acknowledged
the same before me and in my jurisdiction aforesaid.

                                         _________________________
                                                NOTARY PUBLIC
My commission expires:


STATE OF ____________________________

COUNTY OF _________________________

     I, the undersigned, Notary Public, in and for the jurisdiction aforesaid,
do hereby certify that Mark Fowler, Director of Finance and Administration,
whose signature is signed to the foregoing Deed of Lease, personally appeared
before me this _____ day of September 1999, and acknowledged the same before me
in my jurisdiction aforesaid.

                                         _________________________
                                                NOTARY PUBLIC

My Commission Expires:

                                       26
<PAGE>

                                   EXHIBIT C

                             RULES AND REGULATIONS


          1.   The entrance, lobbies, passages, corridors, elevators and
stairways shall not be encumbered or obstructed by Tenant, or Tenant's Agents,
or be used by them for any purpose other than for ingress and egress to and from
the Premises.  Tenant shall not place or permit its Agents to place any trash or
other objects anywhere within the Building or the land (other than within the
Premises) without first obtaining Landlord's written consent.

          2.   No curtains, blinds, shades, screens or signs other than those
furnished by Landlord shall be attached to, hung in or used in connection with
any window or door of the Premises without prior written consent of Landlord.
Interior signs on the suite entry doors shall be painted or affixed for Tenant
by Landlord or by sign painters first approved by Landlord at the expense of
Tenant and shall be of a size, color and style acceptable to Landlord.

          3.   If Landlord has installed or hereafter installs any shade, blind
or curtain in the Premises, Tenant shall not remove the same without first
obtaining Landlord's written consent thereto.

          4.   Canvassing, soliciting and peddling in the Building are
prohibited and Tenant shall cooperate to prevent the same.

          5.   Tenant may request heating and/or air conditioning during periods
in addition to normal working hours by submitting its request in writing to the
Building Manager's office no later than 12:00 p.m. the preceding workday (Monday
through Friday) on forms available from the Building Manager.  The request shall
clearly state the start and stop hours of the "off-hour" service.  Tenant shall
submit to the Building Manager a list of personnel who are authorized to make
such requests.  Charges are to be governed by the provisions of Tenant's Lease.

          6.   The water and wash closets and other plumbing fixtures shall not
be used for any purposes other than those for which they were constructed, and
no sweepings, rubbish bags or other articles/substances (including, without
limitation, coffee grounds) shall be thrown therein.

          7.   No cooking shall be done or permitted in the Building by Tenant
or its Agent except that Tenant may install and use microwave ovens.  Tenant
shall not cause or permit any unusual or objectionable odors to emanate from the
Premises.

          8.   Tenant shall not make or permit any unseemly or disturbing noises
or disturb or interfere with other tenants or occupants of the Building or
neighboring buildings or premises by the use of any musical instrument, radio,
television set, other audio device, unmusical noise, whistling, singing or in
any other way.

          9.   No additional locks or bolts of any kind shall be placed upon any
of the doors or windows of the Premises, nor shall any changes be made in locks
or the mechanism thereof without prior notice to and the approval of Landlord.
Tenant shall, upon the termination of its Lease, return to Landlord all keys to
the Premises and other areas furnished to, or otherwise procured by Tenant.  In
the event of the loss of any such keys, Tenant shall pay Landlord the cost of
replacement keys.

          10.  Tenant shall not use or occupy or permit any portion of the
Premises to be used or occupied as an employment bureau or for the storage,
manufacture or sale of liquor, narcotics, or drugs.  The Premises shall not be
used, or permitted to be used, for lodging or for any immoral or illegal
purpose.

          11.  Landlord reserves the right to control and operate the Common
Area in such manner as it deems best for the benefit of the Building tenants.
Landlord may exclude from all or a part of the Common Area at all hours on
Monday through Friday, except 8:00 a.m. to 6:00 p.m., and at all hours on
Saturday, except 8:00 a.m. to 1:00 p.m., and all day Sunday and federal holidays
other than Columbus Day, all persons who do not present a pass to the Building
signed by Landlord or other suitable identification satisfactory to Landlord.
Landlord will furnish passes to persons for whom Tenant reasonably requests such
passes.  Tenant shall be responsible for all persons for whom it requests such
passes and shall be liable to Landlord for all acts of such persons.

          12.  Tenant shall have the responsibility for the security of the
Premises and, before closing and leaving the Premises at any time, Tenant shall
see that all entrance doors are locked and all lights and office equipment
within the Premises are turned off, and Landlord shall have no responsibility
relating thereto.

                                       27
<PAGE>

          13.  In connection with the delivery or receipt of merchandise,
freight or other matter, no hand trucks or other means of conveyance shall be
permitted, except those equipped with rubber tires, rubber side guards or such
other safeguards as Landlord may require.

          14.  No animals of any kind, except seeing-eye dogs, shall be brought
into or kept about the Land or the Building by Tenant or its Agents.

          15.  So that the Building may be kept in a good state of cleanliness,
Tenant shall permit only Landlord's employees and contractors to clean its
Premises unless prior thereto Landlord otherwise consents in writing.

          16.  Tenant shall keep the windows and doors of the Premises
(including, without limitation, those opening on corridors and all doors between
any room designed to receive heating or air conditioning service and room(s) not
designated to receive such service) closed while the heating or air conditioning
system is operating in order to minimize the energy used by, and to conserve the
effectiveness of, such systems.

          17.  Normal business hours are 8 AM to 6 PM Monday through Friday, 8
AM to 12 Noon Saturday.  Holidays as outlined in Exhibit D are excluded.

                                       28
<PAGE>

                                   EXHIBIT D

                                    HOLIDAYS



January 1 - New Year's Day

President's Day

Memorial Day

July 4 - Independence Day

Labor Day

Thanksgiving Day

December 25 - Christmas Day



          These are the Building's holidays, but Landlord recognizes the Tenant
may be open every day.

                                       29
<PAGE>

                                   EXHIBIT E

                            CLEANING SPECIFICATIONS


A.   General

     1. All cleaning work will be performed between 5 p.m. and 12 midnight,
        Monday through Friday, unless otherwise necessary for stripping, waxing,
        etc.

     2. Abnormal waste removal (e.g., medical or toxic waste, computer
        installation paper, bulk packaging, wood or cardboard crates, refuse
        from cafeteria operation, etc.) shall be Tenant's responsibility.

B.   Daily Operations (5 times per week)

     1. Tenant Area

        a. Empty and clean all waste receptacles; wash receptacles as necessary.

        b. Vacuum all rugs and carpeted areas.

        c. Empty, damp-wipe and dry all ashtrays.

     2. Lavatories

        a. Sweep and wash floors with disinfectant.

        b. Wash both sides of toilet seats with disinfectant.

        c. Wash all mirrors, basins, bowls, urinals.

        d. Spot clean toilet partitions.

        e. Empty and disinfect sanitary napkin disposal receptacle.

        f. Refill toilet tissue, towel, soap, and sanitary napkin
           dispensers.

     3. Public Areas

        a. Wipe down entrance doors and clean glass (interior and exterior).

        b. Vacuum elevator carpets and wipe down doors and walls.

        c. Clean water coolers.

C.   Operations as Needed (but not less than every other day)

     1. Tenant Areas, Lavatories, Public Areas

        a.   Clean all resilient floor areas and bring finish to a shine.

D.   Weekly Operations

     1. Tenant Areas, Lavatories, Public Areas

        a. Hand-dust and wipe clean all horizontal surfaces with treated cloths
           to include furniture, office equipment, window sills, door ledges,
           chair rails, baseboards, convector tops, etc., within normal reach.

        b. Remove finger marks from private entrance doors, light switches, and
           doorways.

        c. Clean and wax, if necessary, all stairways.

                                       30
<PAGE>

E.   Monthly Operations (Or more often as needed)

     1. Tenant and Public Areas

        a. Thoroughly vacuum seat cushions on chairs, sofas, etc.

        b. Vacuum and dust grillwork.

     2. Lavatories

        a. Wash down interior walls and toilet partitions.

F.   As required and Weather Permitting, but not less often than Semi-annually.

     1. Entire Building

        a. Clean inside of all windows.

        b. Clean outside of all windows.

G.   Yearly (Or more often as needed)

     1. Tenant and Public Areas

        a. Strip and wax all resilient tile floor areas.

H.   Cafeteria/Vending Installation

     1. Any space to be used primarily for lunchroom or cafeteria operation will
        be Tenant's responsibility to keep clean and sanitary. This includes
        appliances that are specifically for Tenant's space, i.e., dishwasher,
        refrigerator, washer, dryer, microwave.

     2. If Tenant should at some later date require vending machines, machine
        installation and clean-up are the responsibility of the Tenant.

                                       31
<PAGE>

                                   Exhibit G

                      SMART Dispute Resolution Procedure


I.  Preliminary.

     1.  Any dispute regarding the terms of a contract, agreement, or business
relationship between the parties herein, or involving employees, agents, or
other representatives of the parties, shall be resolved, at the election of
either party, by the following "SMART" procedure ("Sensible Method for
Addressing and Resolving Troubles").

     2.  SMART shall be initiated by one party's sending a certified letter to
the other, requesting a resolution of a dispute described in the letter.  Such a
request shall be made in a timely manner, normally within 3 months after the
event which initiated the dispute.  Any question regarding timeliness, and its
effect on the merits of the claim or costs of and effectiveness of its defense,
shall be decided by the arbitrator(s), and may be a factor in the amount or
appropriateness of any award, their decision to be final. A document request not
to exceed 100 pages in length may accompany such letter.

     3.  Within 14 days after the receipt of such notice, each party shall
designate a representative to meet in formally to attempt to resolve the
dispute.

     In the event that the parties are unable to resolve the matter between them
within 30 days after the date of the initial letter, either party may, by a
second letter served certified mail on the other party, initiate proceedings for
a final and binding resolution of such dispute, controversy or claim by
arbitration following the procedures herein set forth, along with a requested
award.

II.  Arbitration.

     4.  If the award requested is under $50,000, all evidentiary hearings and
decisionmaking shall be accomplished by a single arbiter.

     If the parties cannot agree on the arbiter, within 15 days after the date
of the second letter they shall each appointed a representative, and the two
representatives shall within 10 days jointly nominate the arbiter.  Such arbiter
shall have at least 10 years active prior experience in the business field in
which the dispute arises.

     The arbiter shall issue a written report explaining the award.

     5.  If the award requested is greater than $50,000, or involves relief
other than money damages, upon request of either party, the hearings and
decisionmaking shall be accomplished by two designated representatives, one
appointed by either side, each of which shall have at least 10 years active
prior experience in the business field in which the dispute arises.  Either
party, if it so chooses, may designate a representative employed by, or
otherwise affiliated with, the party so designating.

     Within 10 days of their appointment the designated representatives shall
jointly appoint a neutral arbiter.  Such arbiter shall have had significant
prior experience in dispute resolution, as a judge, lawyer, arbitrator, or
mediator, and prior experience in the business field in which the dispute
arises.

     If an appointment is required and has not been made within the designated
time period, such a choice will be left up to the American Arbitration
Association.

     The parties shall agree prior to the commencement of hearings whether the
neutral arbiter shall participate in the hearings, or shall serve as a final
decisionmaker based on the record only.  If they cannot agree, the neutral
arbiter shall participate in full.

          (i)  if the neutral arbiter does not attend the hearings:

          At the conclusion of the evidence, each designated representative
shall make findings of facts and conclusions of law, together with a suggested
award.

          If the higher of the two suggested awards is within 20% of the lower,
or $30,000, whichever is greater, the amounts shall be compromised and such
amount shall be the final reward. Should the suggested awards differ by more,
the neutral arbiter shall pick one or the other amounts designated by the
designated representatives, but shall not have the power to compromise these
amounts.  A written report by the neutral arbiter will set forth findings of
fact and conclusions of the law in addition to confirming the award.  The
neutral arbiter shall have power to vary the non-monetary aspect of any award.

           (ii)  if the neutral arbiter attends the hearings:

            The panel shall, by majority vote, issue findings of fact and
conclusions of law in connection with its award.

                                       32
<PAGE>

          With either procedure, should the amount of the award exceed $250,000,
or involve non-monetary remedies, either party may appeal the correctness of the
conclusions of law to the Federal Court of E.D. of Virginia.  Findings of fact
shall be subject to judicial review only if they are arbitrary and capricious,
an abuse of discretion, or totally unsupported by the evidence, or deficient in
other similar standards used for judicial review of administrative decisions in
contested cases.  Security for the party receiving an award shall be set by the
court.

III.  General Provisions.

     6.  Evidence.  Rules for discovery, interrogatories, depositions, and other
evidentiary issues and a schedule therefore shall be decided by the arbiter(s),
in accordance with the procedures of the American Arbitration Association or
other rules selected by the arbitrators in their sole discretion.  Each party
shall submit a discovery plan to the arbiter(s) and have it approved prior to
requesting any discovery beyond the initial 100 pages.  Oral depositions shall
be discouraged unless a deponent cannot easily available for actual testimony.
The time periods applicable to discovery shall be set to permit compliance with
the scheduling provisions of 8) below.

     All evidence, whether written or oral, shall be deemed by the parties to be
confidential, and it shall not be disclosed to any other person except to the
extent reasonably necessary to assist counsel in the proceedings or in
preparation for the proceeding.

     7.  Schedule.  The arbitration shall be conducted on an expedited schedule.
Unless otherwise agreed by the parties, the initial submissions shall be made,
and the hearing shall commence, within 45 days of the initiation of the
arbitration.  The hearings shall be completed within 30 days thereafter.  The
award shall be made within 15 days from the close of the hearing.  Any failure
to render the award within the foregoing time period shall not, however, affect
the validity of such awards.

     8.  Validity.  Judgment on the award may be entered in any court having
jurisdiction over the necessary party.  The award of noncompensatory damages, if
made, shall not exceed 50% of compensatory damages and shall be a nonappealable
fact.  The parties hereby waive their right to proceed judicially in any
jurisdiction pending the outcome of the SMART proceedings as outlined above.

     9.  Costs.  Each party shall bear its own costs for representation and
preparation.  The costs for any neutral arbiter shall be shared equally by the
parties.

     Should a party challenge the existence, validity, terms, or enforceability
of these dispute resolution provisions, and if it does not prevail in its
challenge, it shall pay the costs and fees as determined by the arbitrator(s).

     At any time during the proceedings either party shall have the opportunity
to submit an offer for settlement to the opposing party which may be sealed or
presented publicly to the arbiter(s), as the initiating party so chooses.
Subsequent offers may be made earlier ones be rejected.

     Should the final award be more favorable to the party making such offer of
settlement than the pending offer which was not accepted, the party which did
not accept such offer shall pay all costs of arbitration, including without
limitation the cost to the other party of its expert witnesses, discovery costs,
stenographic fees, and attorney's fees.  Such reimbursements, however, shall be
limited to the difference between the offer rejected and the actual award.  The
arbiters shall have the power to award partial costs in the event of a
multifaceted award.

     10.  Supplemental Procedure.  The arbitration shall be governed by such of
the general and special rules of the American Arbitration Association (AAA) in
force as of the date of the proceedings as are not inconsistent with the
provisions herein.  Should any language contained herein require interpretation
beyond the scope of discretion of the arbiter(s), the parties authorize the AAA
to perform this role.

     11.  Review.  Prior to the final issuance of any required written report
prepared as part of an award, a draft of such report shall be circulated to the
parties, giving each the opportunity to comment on the reasoning employed, and
the accuracy of the calculation of the award.  The arbiter shall set time limits
to govern the comment procedure, and may or may not respond to the comments, or
revise the award after reading them.

     12.  Choice of Law.  The law applied shall be that of Virginia, United
States of America, but if sufficient authority in a particular area of the law
is lacking, precedent from other leading industrial states, such as New York,
Illinois, or California, may be invoked.

                                       33
<PAGE>

                                 ADDENDUM ONE

                         UPS/GENERATOR/SATELLITE DISH
                                       --------- ----



1.   UPS/Generator.  Tenant will have the right, at its sole cost, to utilize a
     -------------
     mutually agreed upon area adjacent to the Building to locate their UPS and
     generator at no charge for the Lease Term, provided that (i) Landlord has
     reasonable approval rights (to include structural and aesthetic
     considerations); (ii) Tenant agrees to provide screening of system
     components acceptable to Landlord, if necessary; (iii) Tenant indemnifies
     Landlord against any damage (physical damage and/or through pollutants) to
     the area associated with the installation, maintenance of the system; and
     (iv) Tenant agrees to pay all restoral costs at the end of the Lease Term.

2.   Tenant may install a satellite dish at no additional rental charge,
     -------------------------------------------------------------------
     provided that all applicable laws and regulations are observed and
     ------------------------------------------------------------------
     operation of such equipment are adhered to by Tenant and the satellite dish
     ---------------------------------------------------------------------------
     does not interfere with any satellite dish already existing in Parkridge
     ------------------------------------------------------------------------
     Center and Tenant shall remove all equipment and fully restore said site.
     --------------------------------------------------------------------------
     Landlord shall have the right to review and approve all installation plans
     --------------------------------------------------------------------------
     for the satellite dish and wiring.  Landlord's approval shall not be
     --------------------------------------------------------------------
     unreasonably withheld or delayed.  In the event Tenant does erect a
     -------------------------------------------------------------------
     satellite dish, it shall be at a mutually agreed upon location.  Tenant
     -----------------------------------------------------------------------
     shall be solely responsible for the costs of installation, maintenance and
     --------------------------------------------------------------------------
     removal of any equipment installed hereunder.  Tenant shall provide full
     ------------------------------------------------------------------------
     documentation for the installation, operation, and cabling of such rooftop
     --------------------------------------------------------------------------
     equipment.  At Tenant's election, Tenant may remove such roof top equipment
     ---------------------------------------------------------------------------
     and restore roof to a condition satisfactory to Landlord or Tenant shall
     ------------------------------------------------------------------------
     give Landlord the right to have such equipment surrendered or removed at
     ------------------------------------------------------------------------
     Tenant's cost at the end of the Lease Term pursuant to Article X.
     -----------------------------------------------------------------




g:\peid98\ad1.music.wpd

<PAGE>

                                 ADDENDUM TWO

                            RIGHT OF FIRST REFUSAL



     Tenant shall have the Right of First Refusal for contiguous space  on the
Concourse Level. Provided said Right of First Refusal is exercised within the
first (1/st/) lease year, said expansion shall be provided under the same terms
and conditions as in the initial Lease except that Landlord improvement
allowance shall be pro-rata to the reduced lease term.  Notwithstanding the
foregoing, anytime after the first (1/st/) lease year, said expansion space
shall be provided at the fair market value terms and conditions for lower level,
windowless space for the then remaining Lease Term.  Tenant's expansion rights
shall be void if Tenant is in material default of the Lease continuing at the
time of Tenant's exercise.  Tenant will have ten (10) business days to respond
to Landlord's notice of availability.  In the event Tenant fails to respond
during such ten (10) business day period, the expansion right shall terminate on
the space in question.  The Right of First Refusal option does not convey with
sublet/assignment.





g:\peid98\ad2.music.wpd

<PAGE>

                                ADDENDUM THREE

                                OPTION TO RENEW

     Tenant shall have the option to renew ("Option to Renew") this Lease for
two (2) additional terms of five (5) years at fair market rental rates for
Tenants in comparable office buildings with a portion of windowless space in the
Reston office market, provided, however, that the following conditions shall all
be met: (i) upon the exercise of the Option to Renew, no Event of Default shall
have occurred and be continuing; (ii) that Tenant shall not have any further
option to renew or otherwise extend the Term of this lease beyond the last day
of the last available Renewal Term; (iii) that Tenant shall exercise its option
       --------------
by giving written notice to Landlord of such election not later than nine (9)
months prior to the expiration of the original or first renewal Term, in the
manner and at the place provided for giving notice to Landlord; (iv) that
renewal of this Lease shall be upon the terms, covenants, agreements,
provisions, conditions, and limitations set forth in this Lease, which shall be
as fully applicable during such Renewal Term as they are applicable during the
original Term, except to the extent expressly otherwise provided in this Lease
or Renewal document.  The Option to Renew does not convey with
sublet/assignment.



g:\peid98\ad3.music.wpd
<PAGE>

                           FIRST AMENDMENT TO LEASE


                             MUSICMAKER.COM, INC.


     This First Amendment To Lease made this ___ day of November, 1999 by and
between Parkridge Five Associates Limited Partnership (the "LANDLORD") and
Musicmaker.com, Inc., a Delaware corporation ("TENANT").


                                   WITNESSETH
                                   ----------

     WHEREAS, Landlord and Tenant entered into that certain Lease agreement with
Musicmaker.com, Inc. dated September 27, 1999 (the "LEASE") pursuant to which
Tenant leased 20,566 rentable square feet of commercial office space in the
building located at 10780/10790 Parkridge Boulevard, Reston, Virginia;

     WHEREAS, the Tenant desires to expand their Premises by an additional
10,695 rentable square feet ("First Expansion Space"), located on the Concourse
Level of the Building, for a total of 31,261 rentable square feet.

     WHEREAS, all terms and conditions of the Lease, shall remain in full force
and effect except as otherwise set forth herein.

     NOW THEREFORE, in consideration of One Dollar ($1.00) cash in hand paid and
in further consideration of the foregoing and the respective rights and
obligations hereinafter set forth, Landlord and Tenant agree to modify the Lease
as follows:

1.   Commencement Date for the First Expansion Space shall be April 1, 2000.
--   -----------------

2.   Expiration Date for both the Original Premises and the First Expansion
--   ---------------
     Space will be December 31, 2009.

3.   Basic Rent: Basic Rent for the First Expansion Space will be $26.00 per
--   -----------
     rentable square foot and escalated by three (3%) percent per annum as
     outlined below:

20, 566 - Total Original Premises:
----------------------------------
<TABLE>
<CAPTION>

     Year                                     Per Annum   Per Month     PSF
     ----                                    -----------  ----------  -------
<S>                                         <C>          <C>         <C>
1/1/2000-12/31/2000                          $569,558.00  $47,463.17  $27.69
1/1/2001-12/31/2001                          $586,644.74  $48,887.06  $28.52
1/1/2002-12/31/2002                          $604,244.08  $50,353.67  $29.38
1/1/2003-12/31/2003                          $622,371.40  $51,864.28  $30.26
1/1/2004-12/31/2004                          $641,042.54  $53,420.21  $31.17
1/1/2005-12/31/2005                          $660,273.82  $55,022.82  $32.11
1/1/2006-12/31/2006                          $680,082.03  $56,673.50  $33.07
1/1/2007-12/31/2007                          $700,484.49  $58,373.71  $34.06
1/1/2008-12/31/2008                          $721,499.02  $60,124.92  $35.08
1/1/2009-12/31/2009                          $743,143.99  $61,928.67  $36.13

10,695 rsf - Total First Expansion Space:
-----------------------------------------

<CAPTION>

     Year                                    Per Annum    Per Month   PSF
     ----                                    -----------  ----------  ------
<S>                                         <C>          <C>         <C>
4/1/2000-12/31/2000                          $278,070.00  $23,172.50  $26.00*
-------------------                          -----------  ----------  ------
1/1/2001-12/31/2001                          $286,412.10  $23,867.68  $26.78
-------------------                          -----------  ----------  ------
1/1/2002-12/31/2002                          $295,004.46  $24,583.71  $27.58
-------------------                          -----------  ----------  ------
1/1/2003-12/31/2003                          $303,854.59  $25,321.22  $28.41
-------------------                          -----------  ----------  ------
1/1/2004-12/31/2004                          $312,970.23  $26,080.85  $29.26
-------------------                          -----------  ----------  ------
1/1/2005-12/31/2005                          $322,359.34  $26,863.28  $30.14
-------------------                          -----------  ----------  ------
1/1/2006-12/31/2006                          $332,030.12  $27,669.18  $31.05
-------------------                          -----------  ----------  ------
1/1/2007-12/31/2007                          $341,991.02  $28,499.25  $31.98
-------------------                          -----------  ----------  ------
1/1/2008-12/31/2008                          $352,250.75  $29,354.23  $32.94
-------------------                          -----------  ----------  ------
1/1/2009-12/31/2009                          $362,818.27  $30,234.86  $33.92
-------------------                          -----------  ----------  ------
</TABLE>
* Basic and Additional Rent will be pro-rated for the nine (9) months in 2000.
------------------------------------------------------------------------------
<PAGE>

4.   Tenant's Proportionate Share: Reference Article 1.19 of the Lease, Tenant's
--   ----------------------------
     Proportionate Share for the entire 31,261 rentable square feet will be
     fifteen point three-six percent (15.36%).

5.   Security Deposit: Shall be proportional and at the same rate, terms and
--   ----------------  -----------------------------------------------------
     conditions as the Security Deposit required in the Lease.  Specifically
     -----------------------------------------------------------------------
     calculated as follows: 31,261 square feet/20,566 square feet = 1.52 x
     ---------------------------------------------------------------------
     $620,000 = $942,420.50 total Security Deposit.  Since $620,000 has already
     --------------------------------------------------------------------------
     been received a balance of $322,420.50 is due no later than December 1,
     -----------------------------------------------------------------------
     1999.  Such Security Deposit shall be reduced $91,200 per year pursuant to
     --------------------------------------------------------------------------
     Article V of the Lease (replacing the $60,000 reduction on the Original
     -----------------------------------------------------------------------
     Premises only).
     ---------------

6.   First months' Rent for the First Expansion Space shall be due at Lease
--   ----------------------------------------------------------------------
     Amendment execution, $23,172.50.
     --------------------------------

7.   Tenant Improvements: Landlord will provide to Tenant a Tenant Improvement
--   ------------------- -----------------------------------------------------
     Allowance of $27.00 psf x 10,695 rsf x 117/120 = $26.325 psf = $281,545.88,
     ---------------------------------------------------------------------------
     in a manner as provided in the Lease.
     ------------------------------------

8.   All other terms and conditions of the Lease dated September 27, 1999 shall
--   --------------------------------------------------------------------------
     remain unchanged and in full force and effect.
     ----------------------------------------------

                                       2
<PAGE>

     IN WITNESS WHEREOF, Landlord and Tenant have executed this First Amendment
to Lease under seal as of the Date of the First Amendment to Lease.



ATTEST/WITNESS:                          LANDLORD: Parkridge Five Associates
_______________                          ___________________________________
                                                 Limited Partnership
                                                 ___________________


_____________________________            By:__________________________[SEAL]

Name:________________________            Name: Sunrise Valley, Inc.

Title:_______________________            Title:General Partner
                                               Christopher W. Walker, President

                                         Date:_____________________



ATTEST/WITNESS:                          TENANT:   Musicmaker.com, Inc.
______________                           ______


_____________________________            By:______________________________

Name:  _______________________           Name: Mark Fowler
                                              ____________________________

                                         Title:Vice President
                                               ___________________________
                                               Finance and Administration
                                               ___________________________
                                               and Chief Financial Officer
                                               ___________________________

                                         Date: ___________________________


                                       3
<PAGE>

STATE OF VIRGINIA

COUNTY OF FAIRFAX

     I, the undersigned, Notary Public in and for the jurisdiction aforesaid do
hereby certify that CHRISTOPHER W. WALKER General Partner of Parkridge Five
Associates Limited Partnership, whose signature is signed to the foregoing First
Amendment to Lease, personally appeared before me this _____ day of November,
1999 and acknowledged the same before me and in my jurisdiction aforesaid.

                                         _________________________
                                                NOTARY PUBLIC
My commission expires:



STATE OF VIRGINIA

COUNTY OF FAIRFAX

     I, the undersigned, Notary Public, in and for the jurisdiction aforesaid,
do hereby certify that Mark Fowler, Vice President Finance and Administration
and Chief Financial Officer, whose signature is signed to the foregoing First
Amendment to Lease, personally appeared before me this _____ day of November,
1999 and acknowledged the same before me in my jurisdiction aforesaid.

                                         _________________________
                                                NOTARY PUBLIC

My Commission Expires:


g:\peid98\amend1.music.wpd
<PAGE>

                           SECOND AMENDMENT TO LEASE

                              MUSICMAKER.COM, INC.


     This Second Amendment to Lease made this ___ day of February 2000 by and
between Parkridge Five Associates Limited Partnership (the "LANDLORD") and
Musicmaker.com, Inc., a Delaware corporation ("TENANT").

                                   WITNESSETH
                                   ----------

     WHEREAS, Landlord and Tenant entered into that certain Lease agreement with
Musicmaker.com, Inc. dated September 27, 1999 (the "LEASE") pursuant to which
Tenant leased 20,566 rentable square feet of commercial office space in the
building located at 10780/10790 Parkridge Boulevard, Reston, Virginia;

     WHEREAS, Landlord and Tenant by First Amendment to Lease dated November 22,
1999 ("First Amendment"), in which the rentable square footage was  changed
from20,566  rentable square feet to 31,261 rentable square feet and Tenant's
Proportionate Share was changed from 10.08% to 15.36%.

     WHEREAS, Tenant desires and Landlord agrees to change the Lease
Commencement Date of the Original Lease dated September 27, 1999 to January 15,
2000; the Commencement Date on the First Amendment to Lease dated November 22,
1999 will remain April 1, 2000.  Tenant also desires and Landlord agrees to
extend the Lease Termination Date of the Original Lease and the First Amendment
to Lease from December 31, 2009 to January 14, 2010.

     WHEREAS, all terms and conditions of the Lease, will remain in full force
and effect except as otherwise set forth herein.

     NOW THEREFORE, in consideration of One Dollar ($1.00) cash in hand paid and
in further consideration of the foregoing and the respective rights and
obligations hereinafter set forth, Landlord and Tenant agree to modify the Lease
as follows:

1.   Commencement Date for the Original Lease will be January 15, 2000.
--   -----------------

2.   Expiration Date for both the Original Lease and the First Amendment Space
--   ---------------
     will be January 14, 2010.

3.   Basic Rent: Commencement dates for both the Original Lease and the First
--   -----------
     Amendment to Lease are outlined below:

20, 566 - Total Original Premises:
----------------------------------
<TABLE>
<CAPTION>

    Year                         Per Annum   Per Month     PSF
    ----                         ---------   ---------     ---
<S>                             <C>          <C>         <C>
1/16/2000-1/15/2001             $569,558.00  $47,463.17  $27.69
1/16/2001-1/15/2002             $586,644.74  $48,887.06  $28.52
1/16/2002-1/15/2003             $604,244.08  $50,353.67  $29.38
1/16/2003-1/15/2004             $622,371.40  $51,864.28  $30.26
1/16/2004-1/15/2005             $641,042.54  $53,420.21  $31.17
1/16/2005-1/15/2006             $660,273.82  $55,022.82  $32.11
1/16/2006-1/15/2007             $680,082.03  $56,673.50  $33.07
1/16/2007-1/15/2008             $700,484.49  $58,373.71  $34.06
1/16/2008-1/15/2009             $721,499.02  $60,124.92  $35.08
1/16/2009-1/15/2010             $743,143.99  $61,928.67  $36.13


10,695 rsf - Total First Expansion Space:
-----------------------------------------


    Year                         Per Annum   Per Month     PSF
    ----                         ---------   ---------     ---
<S>                             <C>          <C>         <C>
4/1/2000-1/15/2001               $278,070.00  $23,172.50  $26.00*
------------------               -----------  ----------  -------
1/16/2001-1/15/2002              $286,412.10  $23,867.68  $26.78
-------------------              -----------  ----------  ------
1/16/2002-1/15/2003              $295,004.46  $24,583.71  $27.58
-------------------              -----------  ----------  ------
1/16/2003-1/15/2004              $303,854.59  $25,321.22  $28.41
-------------------              -----------  ----------  ------
1/16/2004-1/15/2005              $312,970.23  $26,080.85  $29.26
-------------------              -----------  ----------  ------
1/16/2005-1/15/2006              $322,359.34  $26,863.28  $30.14
-------------------              -----------  ----------  ------
1/16/2006-1/15/2007              $332,030.12  $27,669.18  $31.05
-------------------              -----------  ----------  ------
1/16/2007-1/15/2008              $341,991.02  $28,499.25  $31.98
-------------------              -----------  ----------  ------
1/16/2008-1/15/2009              $352,250.75  $29,354.23  $32.94
-------------------              -----------  ----------  ------
1/16/2009-1/15/2010              $362,818.27  $30,234.86  $33.92
-------------------              -----------  ----------  ------

</TABLE>

                                       1
<PAGE>

4.   All other terms and conditions of the Original Lease dated September 27,
--   1999 and First Amendment to Lease dated November 22, 1999 will remain
     unchanged and in full force and effect.



     IN WITNESS WHEREOF, Landlord and Tenant have executed this SecondAmendment
to Lease under seal as of the Date of the First Amendment to Lease.



ATTEST/WITNESS:                     LANDLORD: Parkridge Five Associates
---------------                     -----------------------------------
                                              Limited Partnership
                                              -------------------



------------------------            By:______________________________[SEAL]

Name:___________________            Name: Sunrise Valley, Inc.

Title:__________________            Title:  General Partner
                                            Christopher W. Walker, President

                                    Date:_____________________



ATTEST/WITNESS:                     TENANT:   Musicmaker.com, Inc.
--------------                      ------


______________________________      By: ______________________


Name:  _______________________      Name:    Mark Fowler
                                         ---------------------

                                    Title: Vice President
                                          ----------------
                                          Finance and Administration
                                          and Chief Financial Officer
                                          ---------------------------

                                    Date: ___________________

                                       2
<PAGE>

STATE OF VIRGINIA

COUNTY OF FAIRFAX

     I, the undersigned, Notary Public in and for the jurisdiction aforesaid do

hereby certify that CHRISTOPHER W. WALKER General Partner of Parkridge Five

Associates Limited Partnership, whose signature is signed to the foregoing

Second Amendment to Lease, personally appeared before me this _____ day of

February 2000 and acknowledged the same before me and in my jurisdiction

aforesaid.

                                         _________________________
                                                NOTARY PUBLIC
My commission expires:



STATE OF VIRGINIA

COUNTY OF FAIRFAX


     I, the undersigned, Notary Public, in and for the jurisdiction aforesaid,

does hereby certify that Mark Fowler, Vice President Finance and Administration

and Chief Financial Officer, whose signature is signed to the foregoing Second

Amendment to Lease, personally appeared before me this _____ day of February

2000 and acknowledged the same before me in my jurisdiction aforesaid.

                                         _________________________
                                                NOTARY PUBLIC

My Commission Expires:

                                       3
<PAGE>

                                  EXHIBIT A-3

                                 RENT SCHEDULE

<TABLE>
<CAPTION>


YEAR                    PER ANNUM   PER MONTH    PSF
---------------------  -----------  ----------  ------
<S>                    <C>          <C>         <C>

1/1/2000-12/31/2000    $569,558.00  $47,463.17  $27.69

1/1/2001-12/31/2001    $586,644.74  $48,887.06  $28.52

1/1/2002-12/31/2002    $604,244.08  $50,353.67  $29.38

1/1/2003-12/31/2003    $622,371.40  $51,864.28  $30.26

1/1/2004-12/31/2004    $641,042.54  $53,420.21  $31.17

1/1/2005-12/31/2005    $660,273.82  $55,022.82  $32.11

1/1/2006-12/31/2006    $680,082.03  $56,673.50  $33.07

1/1/2007-12/31/2007    $700,484.49  $58,373.71  $34.06

1/1/2008-12/31/2008    $721,499.02  $60,124.92  $35.08

1/1/2009-12/31/2009    $743,143.99  $61,928.67  $36.13

</TABLE>
NOTE:     Basic Rent is escalated annually by three (3%).

          For purposes of this Rent Schedule, we have utilized a weighted
average rent of above grade space at $28.00 psf for 17,421 rsf and below grade
------------------------------------------------------------------------------
space at $26.00 psf for 3,145 rsf for a total of 20,566 rsf at $27.69 per rsf.
------------------------------------------------------------------------------
$27.75 per rentable square foot to calculate the Basic Rent on the square
-------------------------------------------------------------------------
footage both above and below grade on the Concourse Level.  We will re-calculate
--------------------------------------------------------------------------------
the exact rent figures once an exact square footage measurement has been
------------------------------------------------------------------------
determined.
-----------
<PAGE>

                                  EXHIBIT B-1

                                 WORK AGREEMENT


Improvements:
-------------

1.   Landlord to deliver space in "AC Shell" condition as per attached Exhibit
--   -------------------------------------------------------------------------
     B-2, except Landlord shall deliver the first (1/st/) floor in a multi-
     ---------------------------------------------------------------------
     tenant condition as per attached Exhibit B-2(a) to include, but not limited
     ---------------------------------------------------------------------------
     to all fixtures, life safety features and common area corridors complete
     ------------------------------------------------------------------------
     with building standard finishes installed.
     ------------------------------------------

2.   Tenant has selected its own architect/space planner.
--   ----------------------------------------------------

3.   Construction Allowance: $26.00 per rentable square foot of space leased or
--   --------------------------------------------------------------------------
     $1,336,790.00, payable monthly by Landlord on demand upon presentation of
     -------------------------------------------------------------------------
     invoices, General Contractor's and lien releases and other appropriate
     ----------------------------------------------------------------------
     documentation from Tenant.  Landlord shall hold ten (10%) percent retainage
     ---------------------------------------------------------------------------
     from each payment until job is complete (to include punchlist) and an
     ---------------------------------------------------------------------
     additional retainage withheld, to be determined, payable after "as-built"
     -------------------------------------------------------------------------
     drawings and any other construction documents, as may be determined, are
     ------------------------------------------------------------------------
     delivered.  If the cost of construction exceeds Landlord's allowance
     --------------------------------------------------------------------
     payments towards construction invoices shall be paid proportionally, by
     -----------------------------------------------------------------------
     Landlord and Tenant.
     --------------------

4.   Tenant may lower or increase the Construction Allowance by up to $5.00 per
--   --------------------------------------------------------------------------
     RSF (down to $21.00 per RSF or up to $31.00 per RSF) with a corresponding
     --------------------------------------------------------------------------
     lowering or increase of the Base Rental Rate, determined using an annual
     --------------------------------------------------------------------------
     interest rate of ten percent (10%).  The final Construction Allowance and
     --------------------------------------------------------------------------
     Base Rental Rate shall be established in the Lease.
     ---------------------------------------------------

5.   Utilization: (a) Hard and soft costs, including communication cabling; (b)
--   --------------------------------------------------------------------------
     any unused balance shall be placed into a reserve fund for Tenant to draw
     -------------------------------------------------------------------------
     upon from time to time for future renovations or refurbishment.
     ---------------------------------------------------------------

6.   Tenant shall take full responsibility for the proper and timely
--   ---------------------------------------------------------------
     construction of Tenant's tenant improvements.
     ---------------------------------------------

7.   Tenant shall  retain an authorized construction management representative
--   -------------------------------------------------------------------------
     and this party shall be compensated separately by Tenant.
     ---------------------------------------------------------

8.   Tenant agrees, in return for Landlord's full compliance of Exhibit B-3
--   ----------------------------------------------------------------------
     attached hereto, to a construction management or supervisory fee equal to
     -------------------------------------------------------------------------
     five percent (5%) Landlord's Construction Allowance contribution.
     -----------------------------------------------------------------

9.   Detailed base building plans shall be incorporated by reference into the
--   ------------------------------------------------------------------------
     Lease.
     ------

10.  Landlord shall, at its sole cost and expense, ensure that fiber optic cable
---  ---------------------------------------------------------------------------
     is available to Tenant at the Building.
     ---------------------------------------

<PAGE>

                                  EXHIBIT B-2

                              BASE BUILDING SHELL


1.   All utilities (including telephone truck lines into the Building but not
     including installation of telephone systems) for the demised Premises will
     be in place and fully operational prior to Lease Commencement.

2.   The Building standard HVAC system includes providing and installing the
     following scope of work:

     a.   Installation of non-adjustable temperature sensors controlling all
          VAV's, and installation of all duct work to the VAV's, and
          installation of all VAV's.
     b.   Providing and installation an energy management system for the
          Building.

3.   Building standard sprinkler system will be provided and installed with
     the heads turned up.  Modifications to this system to be paid for out of
     Tenant Allowance.

4.   Building fire alarm, smoke detectors, exit lights and other code
     requirements installed per appropriate county code according to a shell
     building final inspection.

5.   Electric power with a minimum of 3.5 watts per square foot available for
                                                ---------------
     lighting and 7.5 watts per square foot available for convenience power.
                            ---------------

6.   Adjustable horizontal mini-blinds installed on all exterior windows
     throughout the Premises.

7.   Any wall surface beneath or above exterior windows to be insulated
     furred, dry walled, taped and bedded and ready to receive paint or other
     finish.

8.   Plumbing tie-ins available in Tenant's Premises.

9.   Provide the main building lobby area, elevators and common or public
     areas such as restrooms with showers, etc., complete with finishes.
<PAGE>

Unit 50                   LEASE ABSTRACT
     --                   --------------


Building:                     Parkridge Five

Tenant:                       Musicmaker.com

Tenant Contact:               Bruce Block

Demised Area:                 20,566 rsf

Pro-Rata Share:               10.08%

Lease Execution Date:         9/27/99

Lease Commencement Date:      1/1/2000 or substantial completion

Lease Expiration Date:        21/31/09

Term:                         Ten (10) years

Basic Rent:

       YEAR                   PER ANNUM        PER MONTH         PSF
       ----                   ---------        ---------         ---

1/1/2000-12/31/2000           $569,558.00      $47,463.17        $27.69

1/1/2001-12/31/2001           $586,644.74      $48,887.06        $28.52

1/1/2002-12/31/2002           $604,244.08      $50,353.67        $29.38

1/1/2003-12/31/2003           $622,371.40      $51,864.28        $30.26

1/1/2004-12/31/2004           $641,042.54      $53,420.21        $31.17

1/1/2005-12/31/2005           $660,273.82      $55,022.82        $32.11

1/1/2006-12/31/2006           $680,082.03      $56,673.50        $33.07

1/1/2007-12/31/2007           $700,484.49      $58,373.71        $34.06

1/1/2008-12/31/2008           $721,499.02      $60,124.92        $35.08

1/1/2009-12/31/2009           $743,143.99      $61,928.67        $36.13


<PAGE>

Late Fee:                     5%

Concession:                   None

Expense Stop:                 Year 2000 actual expenses, adjusted for
                              extraordinary items

Escalator:                    3%

Security Deposit:             $620,000

Relocation Clause:            None

Cancellation Right:           None

Expansion Right:              Right of First Refusal for contiguous space on the
                              Concourse Level

Expansion Notice:             Ten (10) business days to respond

Renewal Option:               2-5 year terms at Fair Market

Renewal Notice Date:          9 month

Guarantor:                    N/A

Landlord Buildout
 Contribution:                $555,282 ($27.00 psf)

Satellite Dish:               Yes, see Addendum One