Exhibit 4.2

                                                                  EXECUTION COPY



                                  VIACOM INC.,

                            VIACOM INTERNATIONAL INC.

                                       AND

                       THE FIRST NATIONAL BANK OF BOSTON,

                                     Trustee

                 -----------------------------------------------


                          FIRST SUPPLEMENTAL INDENTURE

                            Dated as of May 24, 1995



                      To Indenture dated as of May 15, 1995
                                      among
                                  VIACOM INC.,
                            VIACOM INTERNATIONAL INC.
                                       and
                       THE FIRST NATIONAL BANK OF BOSTON,
                                     Trustee

                 -----------------------------------------------


                             Senior Debt Securities

<PAGE>


                  FIRST SUPPLEMENTAL INDENTURE, dated as of May 24, 1995, among
VIACOM INC., a Delaware corporation (the "Company"), VIACOM INTERNATIONAL INC.,
a Delaware corporation (the "Guarantor"), and THE FIRST NATIONAL BANK OF BOSTON,
a national banking association (the "Trustee"), as Trustee under the Indenture
(the "Indenture"), dated as of May 15, 1995, among the Company, the Guarantor
and the Trustee.

                             RECITALS OF THE COMPANY

                  WHEREAS, Section 901(1) of the Indenture permits supplements
thereto without the consent of Holders of Securities to add to the covenants of
the Company for the benefit of all or any series of Securities;

                  WHEREAS, Section 901(4) of the Indenture permits supplements
thereto without the consent of the Holders of Securities to change any
provisions of the Indenture where there are no Securities Outstanding which are
entitled to the benefit of such provision; and

                  WHEREAS, the Company wishes to add to the covenants of the
Company for the benefit of the Holders of all Securities and to make certain
changes to other provisions of the Indenture, unless otherwise specified as
contemplated by Section 301 of the Indenture.

                  NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE
WITNESSETH:

SECTION 1. For purposes of this First Supplemental Indenture, all terms used
herein, unless otherwise defined, shall have the meaning assigned to them in the
Indenture.

SECTION 2. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 101 of the
Indenture shall be amended by deleting the definitions of "Company", "Guarantor"
and "Principal Property" and replacing such definitions with the following
definitions:

                  "Company" means the Person named as the "Company" in the first
         paragraph of this Indenture until a successor Person shall have become
         such pursuant to the applicable provisions of this Indenture, and
         thereafter "Company" shall mean such successor Person.

                  "Guarantor" means the Person named as the "Guarantor" in the
         first paragraph of this Indenture until a successor Person shall have
         become such pursuant to the applicable provisions of this Indenture,
         and thereafter "Guarantor" shall mean such successor Person.

<PAGE>

                  "Principal Property" means any parcel of real property and
         related fixtures or improvements (other than telecommunications
         equipment, including, without limitation, satellite transponders) owned
         by the Company or any Restricted Subsidiary and located in the United
         States, the aggregate book value of which on the date of determination
         exceeds $500 million, other than any such real property and related
         fixtures or improvements which, as determined in good faith by the
         Board of Directors of the Company, is not of material importance to the
         total business conducted by the Company and its Subsidiaries, taken as
         a whole.

SECTION 3. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 101 of the
Indenture shall be amended by adding the following definitions, each in
alphabetical order:

                  "Attributable Debt" means, with regard to a Sale and Leaseback
         Transaction with respect to any Principal Property, the lesser of: (a)
         the fair market value of such property (as determined in good faith by
         the Board of Directors of the Company); or (b) the present value of the
         total net amount of rent required to be paid under such lease during
         the remaining term thereof (including any period for which such lease
         has been extended and excluding any unexercised renewal or other
         extension options exercisable by the lessee, and excluding amounts on
         account of maintenance and repairs, services, taxes and similar charges
         and contingent rents), discounted at the rate of interest set forth or
         implicit in the terms of such lease (or, if not practicable to
         determine such rate, the weighted average interest rate per annum borne
         by the Securities of the applicable series then Outstanding) compounded
         semi-annually. In the case of any lease which is terminable by the
         lessee upon the payment of a penalty, such net amount shall be the
         lesser of the net amount determined assuming termination upon the first
         date such lease may be terminated (in which case the net amount shall
         also include the amount of the penalty, but no rent shall be considered
         as required to be paid under such lease subsequent to the first date
         upon which it may be so terminated) or the net amount determined
         assuming no such termination.

                  "Sale and Leaseback Transaction" means any arrangement with
         any Person providing for the leasing by the Company or any Restricted
         Subsidiary of any Principal Property which has been or is to be sold or
         transferred by the Company or such Restricted Subsidiary to such
         Person; provided however, that "Sale and Leaseback Transaction" shall
         not include such arrangements that were existing on the date hereof or
         at the time any Person

                                       2
<PAGE>

         owning a Principal Property becomes a Restricted Subsidiary (whether by
         acquisition or otherwise, including through merger or consolidation).


SECTION 4. For the benefit of the Holders of the Company's 7.75% Senior Notes
due 2005 only, Section 307 shall be amended by deleting the first paragraph
thereof and replacing such paragraph in its entirety with the following:

                  (a) Unless otherwise provided as contemplated by Section 301
         with respect to any series of Securities, interest on any Registered
         Security which is payable, and is punctually paid or duly provided for,
         on any Interest Payment Date shall be paid, in immediately available
         funds, to the Person in whose name that Security (or one or more
         Predecessor Securities) is registered at the close of business on the
         Regular Record Date for such interest at the office or agency of the
         Company maintained for such purpose pursuant to Section 1002; provided
         however, that each installment of interest on any Registered Security
         may at the Company's option be paid in immediately available funds by
         transfer to an account maintained by the payee located in the United
         States.

SECTION 5. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 501 shall be
amended by deleting subparagraph (5) and replacing such paragraph in its
entirety with the following:

                  (5) the entry by a court having jurisdiction in the premises
         of a money judgment in an amount in excess of $100 million against the
         Company which has become final and not subject to appeal, and the
         continuance of any such judgment unstayed, in effect and unpaid for a
         period of 60 days; or

SECTION 6. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Sections 501, 502 and
507 of the Indenture shall be amended by deleting the reference to "331/3%" in
each of those sections and replacing such references with "25%".

SECTION 7. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 504 of the
Indenture shall be amended by deleting the last paragraph thereof and replacing
such paragraph in its entirety with the following:

                  Subject to Article Eight and Section 902, nothing herein
         contained shall be deemed to authorize the Trustee to authorize or
         consent to or accept or adopt on behalf of any Holder of a Security or
         of a coupon any plan of

                                       3
<PAGE>

         reorganization, arrangement, adjustment or composition affecting the
         Securities or coupons or the rights of any such Holder thereof or to
         authorize the Trustee to vote in respect of the claim of any such
         Holder in any such proceeding.


SECTION 8. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Article Eight of the
Indenture shall be amended by adding the following covenant:


                                  ARTICLE EIGHT

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

         Section 801. Company and Guarantor May Consolidate, etc. Only on
Certain Terms.

                  Neither the Company nor the Guarantor may consolidate or merge
         with or into another corporation, or sell or convey all or
         substantially all of their respective property and assets to another
         Person unless: (i) immediately after such consolidation, merger, sale
         or conveyance no Event of Default or Default shall have occurred and be
         continuing; (ii) the Person (if other than the Company or the
         Guarantor, as the case may be) is a corporation organized under the
         laws of the United States or any state thereof; (iii) the Person (if
         other than the Company or the Guarantor, as the case may be) through a
         supplemental indenture assumes payment of the principal of (premium, if
         any, on) and interest on, the Outstanding Securities of the applicabale
         series and the performance and observance of all the covenants and
         conditions of the Indenture with respect to the Company or the
         Guarantor, as the case may be; (iv) the Company or the Guarantor, as
         the case may be, shall have delivered to the Trustee an Officer's
         Certificate and an Opinion of Counsel, each stating that such
         consolidation, merger, sale or conveyance and such supplemental
         indenture comply with the applicable provisions of the Indenture and
         that all conditions precedent therein provided for relating to such
         consolidation, merger, sale or conveyance have been complied with. The
         Company and/or the Guarantor may consolidate or merge with or into, or
         sell or convey all or substantially all of their respective property
         and assets to, each other or any Subsidiary of either of them. For
         purposes of this Section, "sell or convey all or substantially all of
         their respective property and assets" shall mean property and assets
         contributing in the aggregate at least 80% of the Company's total
         consolidated revenues as reported in the Company's last available
         periodic financial report (quarterly or annual, as the case may be)
         filed with the Commission.

                                       4
<PAGE>

                  Section 802. Successor Person Substituted.

                  Upon any consolidation by the Company or the Guarantor with or
         merger by the Company or Guarantor into any other corporation or any
         sale or conveyance of all or substantially all of the property and
         assets of the Company or the Guarantor to any Person in accordance with
         Section 801, the successor Person formed by such consolidation or into
         which the Company or the Guarantor is merged or to which such sale or
         conveyance is made shall succeed to, and be substituted for, and may
         exercise every right and power of, the Company or the Guarantor, as the
         case may be, under this Indenture with the same effect as if such
         successor Person had been named as the Company or the Guarantor, as the
         case may be, herein, and in the event of any such sale or conveyance,
         the Company or the Guarantor, as the case may be (which terms shall for
         this purpose mean the Person named as the "Company" or the "Guarantor"
         in the first paragraph of this Indenture or any successor Person which
         shall theretofore become such in the manner described in Section 801)
         shall be discharged of all obligations and covenants under this
         Indenture and the Securities and any coupons appertaining thereto or
         the Guarantees, as the case may be, and may be dissolved or liquidated.

SECTION 9. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 901 of the
Indenture shall be amended by adding the following purpose as new subparagraph
(8) thereof and renumbering the existing subparagraph (8) as subparagraph (9):

                  (8) to evidence the succession of another Person to the
         Company or the Guarantor and the assumption by any such successor of
         the covenants of the Company or the Guarantor, as the case may be,
         herein and in the Securities and the Guarantees in accordance with
         Article Eight hereof; or

SECTION 10. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Section 902(1) of the
Indenture shall be amended by deleting the first parenthetical thereof and
replacing such parenthetical in its entirety with the following:

                  (except as contemplated by Section 801(1) and permitted by
         Section 901(8))

SECTION 11. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Article Ten of the
Indenture shall be amended by deleting the clause "Subject to any supplemental
indentures hereto or Officer's Certificates

                                       5
<PAGE>

creating any series," in Section 1004 and replacing such clause in its entirety
with "Subject to Article Eight," and by adding the following covenants:

                  Section 1010.  Limitations on Liens.

                  The Company shall not create, assume or suffer to exist any
         Lien on any of its property or assets, without securing the Securities
         of any applicable series equally and ratably with (or prior to) such
         secured Indebtedness; provided however, that the foregoing shall apply
         only to Liens which in the aggregate exceed 15% of the Company's Total
         Consolidated Assets as of the end of the Company's most recent
         accounting period preceding the creation or assumption of any such Lien
         (reduced by any Attributable Debt with respect to any Sale and
         Leaseback Transaction permitted under clause (c) of, but not otherwise
         permitted under, Section 1011 below). This restriction will not apply
         to Capitalized Leases or to Indebtedness secured by (a) Liens existing
         on the date hereof and Liens on property of, or Indebtedness of, any
         Person at the time such Person becomes a Subsidiary (whether by
         acquisition or otherwise, including through merger or consolidation),
         (b) Liens in favor of the Company or a Subsidiary of the Company, (c)
         Liens existing at the time of acquisition of the assets secured thereby
         (including acquisition through merger or consolidation) and purchase
         money Liens, and (d) any extension, renewal or refunding of any Lien
         referred to in the foregoing clauses (a) through (c), inclusive.

                  Section 1011.  Limitations on Sale and Leaseback Transactions.

                  The Company shall not, and shall not permit any Restricted
         Subsidiary to, enter into any Sale and Leaseback Transaction with
         respect to any Principal Property unless (a) such Sale and Leaseback
         Transaction involves a lease for a term of not more than three years;
         (b) such Sale and Leaseback Transaction is between the Company and a
         Subsidiary of the Company or between Subsidiaries of the Company; (c)
         the Company or such Restricted Subsidiary would be entitled to incur
         indebtedness secured by a Lien on such Principal Property involved in
         such Sale and Leaseback Transaction at least equal in amount to the
         Attributable Debt with respect to such Sale and Leaseback Transaction
         pursuant to the first sentence of the "Limitations on Liens" covenant
         in Section 1010 above without equally and ratably securing the
         Securities of any applicable series pursuant to such covenant; (d) the
         proceeds of such Sale and Leaseback Transaction are at least equal to
         the fair market value thereof (as determined in good faith by the Board
         of Directors of the Company) and the Company applies an amount equal to
         the greater of the net proceeds of such sale or the Attributable Debt
         with respect to such Sale and Leaseback

                                       6
<PAGE>

         Transaction within 180 days of such sale to either (or a combination)
         of (i) the retirement (other than the mandatory retirement, mandatory
         prepayment or sinking fund payment or by payment at maturity) of debt
         for borrowed money of the Company or a Subsidiary of the Company that
         matures more than 12 months after its creation (other than debt that is
         subordinated to the Securities or debt to the Company or a Subsidiary
         of the Company) or (ii) the purchase, construction or development of
         other comparable property; or (e) such Sale and Leaseback Transaction
         is entered into within 180 days after the initial acquisition by the
         Company or such Restricted Subsidiary, as the case may be, of the
         Principal Property subject to such Sale and Leaseback Transaction.

SECTION 12. For the benefit of the Holders of all Securities, unless otherwise
specified as contemplated by Section 301 of the Indenture, Sections 1502 and
1503 of the Indenture shall be applicable to all Securities. Section 1503 of the
Indenture shall apply to the covenants set forth in Sections 1004, 1005, 1006,
1010 and 1011 of the Indenture as they apply to the Securities of any series.

SECTION 13.  THE LAWS OF THE STATE OF NEW YORK SHALL GOVERN THIS
FIRST SUPPLEMENTAL INDENTURE.

SECTION 14. This First Supplemental Indenture may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original,
but such counterparts shall together constitute but one and the same instrument.

                                       7
<PAGE>

                  IN WITNESS WHEREOF, the parties have caused this First
Supplemental Indenture to be duly executed and attested, all as of the day and
year first written above.


                                      VIACOM INC.


                                      By:  /s/  Vaughn A. Clarke
                                         ---------------------------------------
                                         Name:  Vaughn A. Clarke
                                         Title: Senior Vice President, Treasurer

ATTEST:

By:  /s/  Lawrence Rubin
   -----------------------------
   Name:  Lawrence Rubin
   Title: Assistant Secretary



                                      VIACOM INTERNATIONAL INC.


                                      By:  /s/  Vaughn A. Clarke
                                         ---------------------------------------
                                         Name:  Vaughn A. Clarke
                                         Title: Senior Vice President, Treasurer

ATTEST:

By:  /s/  Lawrence Rubin
   -----------------------------
   Name:  Lawrence Rubin
   Title: Assistant Secretary

                                      THE FIRST NATIONAL BANK OF BOSTON


                                      By:  /s/  James E. Schultz
                                         ---------------------------------------
                                         Name:  James E. Schultz
                                         Title: Account Manager

ATTEST:

By:  /s/  Emily Grier Lea
   -----------------------------
   Name:  Emily Grier Lea
   Title: Account Manager

                                       8
<PAGE>