<PAGE>

                                                                    Exhibit 10.1

                                FIFTH AMENDMENT
                                ---------------

          FIFTH AMENDMENT (this "Amendment"), dated as of May 15, 2001, to the
                                 ---------
Credit and Guaranty Agreement, dated as of March 18, 1999, as amended by the
First Amendment and Consent, dated as of July 1, 1999, the Second Amendment and
Consent, dated as of October 26, 1999, the Third Amendment, dated as of January
14, 2000 and the Fourth Amendment and Waiver, dated as of August 2, 2000 (as the
same may be further amended, supplemented or otherwise modified from time to
time, the "Credit Agreement"), among Muzak LLC, formerly known as Audio
           ----------------
Communications Network, LLC (the "Borrower"), Muzak Holdings LLC ("Holdings")
                                  --------                         --------
and certain Subsidiaries of the Borrower (the "Guarantors"), various Lenders
                                               ----------
from time to time party thereto, Goldman Sachs Credit Partners L.P. ("GSCP"), as
                                                                      ----
Syndication Agent, Canadian Imperial Bank of Commerce, as Administrative Agent
(the "Administrative Agent"), and GSCP and CIBC Oppenheimer Corp., as Co-Lead
      --------------------
Arrangers.

                                    RECITALS
                                    --------

          WHEREAS, capitalized terms used herein which are not herein defined
shall have the meanings ascribed thereto by the Credit Agreement; and

          WHEREAS, the Borrower and Lenders desire to make certain amendments as
set forth below.

          THEREFORE, in consideration of the foregoing and the covenants and
conditions hereinafter set forth, and for other good and valuable consideration,
the receipt and adequacy of which are hereby acknowledged, the parties hereto
agree as follows:

          1.   Amendments to Credit Agreement.
               ------------------------------

          (a)  Applicable Margin. The first sentence of the definition of
               -----------------
"Applicable Margin" in Section 1.1 of the Credit Agreement is hereby amended to
read in its entirety as follows:

               "'Applicable Margin' means (i) a percentage, per annum,
          determined by reference to the Total Leverage Ratio in effect from
          time to time as set forth below:

               ========================================================
                       Tranche A Term Loans and Revolving Loans
               --------------------------------------------------------
                    Total          Applicable            Applicable
                  Leverage    Alternate Base Rate    Eurodollar Rate
                    Ratio            Margin               Margin
               --------------------------------------------------------
                ** 5.25:1.00         2.50%                 3.50%
               --------------------------------------------------------


** Grater than or equals to
<PAGE>

               ========================================================
                       Tranche A Term Loans and Revolving Loans
               --------------------------------------------------------
                  * 5.25:1.00              2.25%              3.25%
                 ** 4.75:1.00
               --------------------------------------------------------
                  * 4.75:1.00              2.00%              3.00%
                 ** 4.25:1.00
               --------------------------------------------------------
                  * 4.25:1.00              1.75%              2.75%
                 ** 3.75:1.00
               --------------------------------------------------------
                  * 3.75:1.00              1.50%              2.50%
               ========================================================


          (ii) with respect to Tranche B Term Loans (a) 4.00% per annum for
          Eurodollar Rate Loans and (b) 3.00% per annum for Alternate Base Rate
          Loans."

          (b)  Interest Coverage Ratio. Section 6.6(a) of the Credit Agreement
               -----------------------
is hereby amended by deleting the table contained therein and substituting the
following therefor:

               ===================================
                             Period                        Ratio
               --------------------------------------------------------
                    Closing Date - 12/31/99              1.60:1.00
               --------------------------------------------------------
                        1/1/00 - 3/31/00                 1.80:1.00
               --------------------------------------------------------
                       4/1/00 - 12/31/00                 1.65:1.00
               --------------------------------------------------------
                        1/1/01 - 9/30/01                 1.80:1.00
               --------------------------------------------------------
                       10/1/01 - 6/30/02                 2.00:1.00
               --------------------------------------------------------
                        7/1/02 - 6/30/03                 2.25:1.00
               --------------------------------------------------------
                     7/1/03 and thereafter               2.50:1.00
               ========================================================

          2.   Effectiveness. This Amendment shall not be effective until such
               -------------
time as (a) the (i) Credit Parties, (ii) Administrative Agent, and (iii)
Requisite Lenders shall have indicated their consent by the execution and
delivery of the signature pages hereof to Administrative Agent, and (b) Borrower
shall have paid all accrued costs, fees and expenses of each Agent in connection
with this Amendment, including, without limitation, all accrued fees and
expenses of counsel to Agents.


          3.   Representations and Warranties of Each Credit Party. Each Credit
               ---------------------------------------------------
Party hereby represents and warrants to the Administrative Agent and the Lenders
that:

*  Less than
** Greater than or equals to

                                       2
<PAGE>

          (a) the execution, delivery and performance of this Amendment have
been duly authorized by all necessary action on the part of each Credit Party.
The execution, delivery and performance by each Credit Party of this Amendment
and the consummation of the transactions contemplated by this Amendment do not
and will not (a) violate any provision of any law or governmental rule or
regulation applicable to such Credit Party, the Organizational Documents of such
Credit Party, or any order, judgment or decree of any court or other agency of
governmental binding on any Credit Party, (b) conflict with, result in a breach
of or constitute (with due notice or lapse of time or both) a default under any
Contractual Obligation of any Credit Party (including, without limitation, the
Senior Subordinated Note Indenture), (c) result in or require the creation or
imposition of any Lien upon any of the properties or assets of any Credit Party
or any of its Subsidiaries, or (d) require the approval of members of any Credit
Party or any approval or consent of any Person under any Contractual Obligation,
except for such approvals or consents which will be obtained on or before the
date hereof and disclosed in writing to the Lenders and except for any such
approvals or consents the failure of which to obtain will not have a Material
Adverse Effect;

          (b) this Amendment and each Credit Document has been duly executed and
delivered by each Credit Party and is the legally valid and binding obligation
of such Credit Party, enforceable against such Credit Party in accordance with
its respective terms, except as may be limited by bankruptcy, insolvency,
reorganization, moratorium or similar laws relating to or limiting creditors'
rights generally or by equitable principles relating to enforceability;


          (c)  on or as of the date hereof, and after giving effect to this
Amendment and the transactions contemplated hereunder, no Default or Event of
Default has occurred and is continuing; and

          (d)  the representations and warranties of each Credit Party contained
in the Credit Agreement and the Credit Documents are true and correct on and as
of the date hereof as if made on and as of the date hereof, except to the extent
such representations and warranties expressly relate to a specific date.

          4.   Acknowledgments and Covenants of Each Credit Party. Each Credit
               --------------------------------------------------
Party hereby (a) reaffirms and admits the validity and enforceability of the
Credit Agreement and the other Credit Documents and all of its obligations
thereunder, (b) agrees and admits that it has no defenses to or offsets against
any of its obligations to the Administrative Agent or any Lender under the
Credit Documents, and (c) agrees to pay all of expenses of the Co-Agents
(including counsel fees and disbursements) incurred in connection with the
preparation, negotiation and completion of this Amendment.

          5.   Status of Credit Documents. This Amendment is limited solely for
               --------------------------
the purposes and to the extent expressly set forth herein, and, except as
expressly modified hereby, the terms, provisions and conditions of the Credit
Documents and the Liens granted thereunder shall continue in full force and
effect and are hereby ratified and confirmed in all respects.

                                       3
<PAGE>

          6.   Counterparts. This Amendment may be executed in any number of
               ------------
counterparts all of which, taken together, shall constitute one Amendment. In
making proof of this Amendment, it shall only be necessary to produce the
counterpart executed and delivered by the party to be charged.

          7.   Governing Law. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF
               -------------
THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED
IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO CONFLICT
OF LAWS PRINCIPLES THEREOF.



                 [Remainder of page intentionally left blank]

                                       4
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.


                                           MUZAK LLC



                                           By: /s/ Michael F. Zendan II
                                              ---------------------------
                                              Name:  Michael F. Zendan II
                                              Title: Vice President and
                                                      General Counsel

 By signing below, the Guarantors (w) ratify and reaffirm the Credit Documents
 to which they are a party, (x) acknowledge this Amendment and (y) agree and
 admit that they have no defenses or offsets against any of their obligations to
 the Administrative Agent or any Lender under the Credit Documents.

MUZAK HOLDINGS LLC                            BUSINESS SOUND, INC.


By: /s/ Michael F. Zendan II                  By: /s/ Michael F. Zendan II
   ----------------------------                  ---------------------------
   Name:  Michael F. Zendan II                   Name:  Michael F. Zendan II
   Title: Vice President and                     Title: Vice President and
           General Counsel                               General Counsel





MUZAK CAPITAL CORPORATION                     BI ACQUISITION, LLC



By: /s/ Michael F. Zendan II                  By: /s/ Michael F. Zendan II
   ---------------------------                   ---------------------------
   Name:  Michael F. Zendan II                   Name:  Michael F. Zendan II
   Title: Vice President and                     Title: Vice President and
           General Counsel                               General Counsel




MLP ENVIRONMENTAL MUSIC, LLC                 AUDIO ENVIRONMENTS, INC.



By: /s/ Michael F. Zendan II                 By: /s/ Michael F. Zendan II
   ---------------------------                  ---------------------------
   Name:  Michael F. Zendan II                  Name:  Michael F. Zendan II
   Title: Vice President and                    Title: Vice President and
           General Counsel                              General Counsel


                                      S-1
<PAGE>

ELECTRO-SYSTEMS CORPORATION                  TELEPHONE AUDIO PRODUCTIONS, INC.



By: /s/ Michael F. Zendan II                 By: /s/ Michael F. Zendan II
    --------------------------                   --------------------------
    Name: Michael F. Zendan II                   Name: Michael F. Zendan II
    Title: Vice President and                    Title: Vice President and
            General Counsel                              General Counsel




BACKGROUND MUSIC                             VORTEX SOUND COMMUNICATIONS
   BROADCASTERS, INC.                         COMPANY, INC.



By: /s/ Michael F. Zendan II                 By: /s/ Michael F. Zendan II
    --------------------------                   --------------------------
    Name: Michael F. Zendan II                   Name: Michael F. Zendan II
    Title: Vice President and                    Title: Vice President and
            General Counsel                              General Counsel



MUZAK HOUSTON, INC.                           MUSIC INCORPORATED



By: /s/ Michael F. Zendan II                  By: /s/ Michael F. Zendan II
    --------------------------                    --------------------------
    Name: Michael F. Zendan II                    Name: Michael F. Zendan II
    Title: Vice President and                     Title: Vice President and
            General Counsel                               General Counsel


                                      S-2
<PAGE>

                                        CANADIAN IMPERIAL BANK OF COMMERCE,
                                        as Administrative Agent and a Lender



                                        By: /s/ Matthew Jones
                                            --------------------------
                                            Name:  Matthew Jones
                                            Title: Managing Director


                                      S-3
<PAGE>

                                        GOLDMAN SACHS CREDIT PARTNERS L.P.,
                                         as Syndication Agent and a Lender



                                        By: /s/ Stephen King
                                           -----------------------------
                                               Authorized Signatory

                                      S-4
<PAGE>

                                        FLEET NATIONAL BANK,



                                        By:_____________________________
                                           Name:
                                           Title:

                                      S-5
<PAGE>

                                        MAGNETITE ASSET INVESTORS,



                                        By: /s/ Mark J. Williams
                                            -----------------------------
                                            Name:  Mark J. Williams
                                            Title: Director


                                      S-6
<PAGE>

                                        TITANIUM CBO,



                                        By: /s/ Mark J. Williams
                                            ---------------------------
                                            Name:  Mark J. Williams
                                            Title: Director


                                      S-7
<PAGE>

                                        SENIOR LOAN FUND,


                                        By: /s/ Mark J. Williams
                                            ----------------------------
                                            Name:  Mark J. Williams
                                            Title: Director


                                      S-8
<PAGE>

                                        COAST BUSINESS CREDIT,



                                        By:_____________________________
                                           Name:
                                           Title:

                                      S-9
<PAGE>

                                        KZH CYPRESSTREE 1-LLC,



                                        By:_____________________________
                                           Name:
                                           Title:

                                      S-10
<PAGE>

                                        KZH CNC LLC,



                                        By:_____________________________
                                           Name:
                                           Title:

                                      S-11
<PAGE>

                                  CYPRESSTREE INVESTMENT PARTNERS I, LTD
                                  By: CypressTree Investment Management Company,
                                  Inc.
                                     as Portfolio Manager



                                  By: /s/ Jeffery W. Heuer
                                      ----------------------------------
                                      Name:  Jeffery W. Heuer
                                      Title: Principal


                                      S-12
<PAGE>

                                  CYPRESSTREE INVESTMENT FUND, LLC
                                  By: CypressTree Investment Management Company,
                                  Inc.
                                     its Managing Manager



                                  By: /s/ Jeffery W. Heuer
                                      --------------------------
                                      Name:  Jeffery W. Heuer
                                      Title: Principal


                                      S-13
<PAGE>

                                  CYPRESSTREE INVESTMENT MANAGEMENT
                                   COMPANY, INC.
                                  As: Attorney-in-Fact and on behalf of
                                      First Allmerica Financial Life Insurance
                                      Company as Portfolio Manager



                                  By: /s/ Jeffery W. Heuer
                                      -------------------------------
                                      Name:  Jeffery W. Heuer
                                      Title: Principal


                                      S-14
<PAGE>

                            CYPRESSTREE SENIOR FLOATING RATE FUND
                            By: CypressTree Investment Management Company, Inc.
                                as Portfolio Manager



                            By: /s/ Jeffery W. Heuer
                                --------------------------------------
                                Name:  Jeffery W. Heuer
                                Title: Principal


                                      S-15
<PAGE>

                            NORTH AMERICAN SENIOR FLOATING
                              RATE FUND,
                            By: CypressTree Investment Management Company, Inc.
                                as Portfolio Manager



                                        By:  /s/ Jeffery W. Heuer
                                             -------------------------------
                                             Name:  Jeffery W. Heuer
                                             Title: Principal


                                      S-16
<PAGE>

                                        FREMONT INVESTMENT & LOAN,



                                        By: /s/ Maria Chachere
                                            --------------------------------
                                            Name:  Maria Chachere
                                            Title: Vice President



                                      S-17
<PAGE>

                                        MERRILL LYNCH
                                         SENIOR FLOATING RATE FUND II, INC.,



                                        By: /s/ Joseph P. Matteo
                                            --------------------------------
                                            Name:  Joseph P. Matteo
                                            Title: Authorized Signatory



                                      S-18
<PAGE>

                                        MERRILL LYNCH
                                           SENIOR FLOATING RATE FUND INC.,



                                        By: /s/ Joseph P. Matteo
                                            --------------------------------
                                            Name:  Joseph P. Matteo
                                            Title: Authorized Signatory



                                      S-19
<PAGE>

                                   MERRILL LYNCH GLOBAL INVESTMENT SERIES:
                                    BANK LOAN PORTFOLIO
                                   By: Merrill Lynch Investment Managers, L.P.
                                      as Investment Advisor



                                   By: /s/ Joseph P. Matteo
                                       ---------------------------------
                                       Name:  Joseph P. Matteo
                                       Title: Authorized Signatory



                                      S-20
<PAGE>

                                   MERRILL LYNCH PRIME RATE PORTFOLIO
                                   By: Merrill Lynch Investment Managers, L.P.
                                      as Investment Advisor



                                   By: /s/ Joseph P. Matteo
                                       --------------------------------
                                       Name:  Joseph P. Matteo
                                       Title: Authorized Signatory



                                      S-21
<PAGE>

                                   SENIOR HIGH INCOME PORTFOLIO, INC.,



                                   By: /s/ Joseph P. Matteo
                                       ---------------------------------
                                       Name:  Joseph P. Matteo
                                       Title: Authorized Signatory



                                      S-22
<PAGE>

                                   WINGED FOOT FUNDING TRUST,



                                   By: /s/ Ann E. Morris
                                       -------------------------------
                                       Name:  Ann E. Morris
                                       Title: Authorized Agent


                                      S-23
<PAGE>

                                   SRF TRADING INC.,



                                   By: /s/ Ann E. Morris
                                       ------------------------------------
                                       Name:  Ann E. Morris
                                       Title: Asst. Vice President


                                      S-24
<PAGE>

                                   NEW YORK LIFE INSURANCE COMPANY,



                                   By:  _____________________________
                                        Name:
                                        Title:

                                      S-25
<PAGE>

                                   Sankaty Advisors, LLC as Collateral Manager
                                   for GREAT POINT CLO 1999-1 LTD, as Term
                                   Lender,



                                   By: /s/ Diane J. Exter
                                       ------------------------------------
                                       Name:  Diane J. Exter
                                       Title: Managing Director
                                              Portfolio Manager


                                      S-26
<PAGE>

                                   STEIN ROE & FARNHAM CLO I LTD.
                                   By Stein Roe & Farnham Incorporated
                                      as Portfolio Manager



                                   By: /s/ Kathleen A. Zarn
                                       ---------------------------------
                                       Name:  Kathleen A. Zarn
                                       Title: Vice President


                                      S-27
<PAGE>

                          STEIN ROE FLOATING RATE
                           LIMITED LIABILITY COMPANY,
                          By Stein Roe & Farnham Incorporated
                             as Advisor



                          By: /s/ Kathleen A. Zarn
                              --------------------------------------
                              Name:  Kathleen A. Zarn
                              Title: Vice President
                                     Stein Roe & Farnham Incorporated
                                     as Advisor to the Stein Roe Floating Rate
                                     Limited Liability Company


                                      S-28
<PAGE>

                                   LIBERTY-STEIN ROE ADVISOR
                                    FLOATING RATE ADVANTAGE FUND,
                                   By: Stein Roe as Advisor



                                   By: /s/ Kathleen A. Zarn
                                       ----------------------------------
                                       Name:  Kathleen A. Zarn
                                       Title: Vice President


                                      S-29
<PAGE>

                                   THE TORONTO DOMINION BANK,



                                   By: /s/ Dana Schwalie
                                       -----------------------------
                                       Name:  Dana Schwalie
                                       Title: Manager, Credit Admin.


                                      S-30
<PAGE>

                                   VAN KAMPEN PRIME RATE INCOME TRUST,



                                   By: /s/ Douglas L. Winchell
                                       -------------------------------
                                       Name:  Douglas L. Winchell
                                       Title: Vice President


                                      S-31
<PAGE>

                                   APEX (IDM) CDO I, LTD.,



                                   By: /s/ Mark K. Misenheimer
                                       ----------------------------------
                                       Name:  Mark K. Misenheimer
                                       Title: S.V.P.


                                      S-32
<PAGE>

                                           TRYON CLO LTD. 2000-I,



                                           By: /s/ Mark K. Misenheimer
                                               ------------------------------
                                               Name:  Mark K. Misenheimer
                                               Title: S.V.P.


                                     S-33
<PAGE>

                                            ELC (CAYMAN) LTD. CDO SERIES 1999-I,



                                            By: /s/ Mark K. Misenheimer
                                                -------------------------------
                                                Name:  Mark K. Misenheimer
                                                Title: S.V.P.


                                     S-34
<PAGE>

                                   ELC (CAYMAN) LTD. CDO SERIES 1999-III,



                                   By: /s/ Mark K. Misenheimer
                                       --------------------------------
                                       Name:  Mark K. Misenheimer
                                       Title: S.V.P.



                                     S-35
<PAGE>

                                   ELC (CAYMAN) LTD. 1999-II,



                                   By: /s/ Mark K. Misenheimer
                                       --------------------------------
                                       Name:  Mark K. Misenheimer
                                       Title: S.V.P.


                                     S-36
<PAGE>

                                   ELC (CAYMAN) LTD.,



                                   By: /s/ Mark K. Misenheimer
                                       -------------------------------
                                       Name:  Mark K. Misenheimer
                                       Title: S.V.P.


                                     S-37
<PAGE>

                                   KATONAH I, LTD.,



                                   By: /s/ Ralph Della Rocca
                                       -----------------------------
                                       Name:  Ralph Della Rocca
                                       Title: Authorized Officer
                                              Katonah Capital, LLC
                                              As Manager


                                     S-38
<PAGE>

                                   KATONAH II, LTD.,



                                   By: /s/ Ralph Della Rocca
                                       -------------------------------
                                       Name:  Ralph Della Rocca
                                       Title: Authorized Officer
                                              Katonah Capital LLC
                                              As Manager


                                     S-39
<PAGE>

                                   SIERRA CLO I LTD.,



                                   By: /s/ John M. Casparian
                                       --------------------------------
                                       Name:  John M. Casparian
                                       Title: Chief Operating Officer
                                              Centre Pacific LLP (Manager)


                                     S-40