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                                                                   EXHIBIT 4.8.5

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                               AMFM OPERATING INC.


                                   AS OBLIGOR


                                       AND

                           THE GUARANTORS NAMED HEREIN

                                       AND

                       U.S. TRUST COMPANY OF TEXAS, N.A.,


                                   AS TRUSTEE


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



                          FOURTH SUPPLEMENTAL INDENTURE

                          DATED AS OF NOVEMBER 19, 1999

                                       TO

                                    INDENTURE


                            DATED AS OF JUNE 24, 1997


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



                                  $200,000,000

                    8 3/4% SENIOR SUBORDINATED NOTES DUE 2007



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         FOURTH SUPPLEMENTAL INDENTURE dated as of November 19, 1999, among AMFM
OPERATING INC., a Delaware corporation (formerly Capstar Communications, Inc.,
the "Company"), the subsidiaries listed on Schedule I hereto (collectively, the
"New Subsidiary Guarantors") and U.S. TRUST COMPANY OF TEXAS, N.A., a national
banking association, as Trustee (the "Trustee").

         WHEREAS, Chancellor Radio Broadcasting Company ("CRBC") (which, prior
to February 14, 1996, was known as Chancellor Broadcasting Company) and certain
guarantors have heretofore executed and delivered to the Trustee an Indenture
dated as of June 24, 1997, as amended by that certain First Supplemental
Indenture dated as of September 5, 1997 by and among Chancellor Media
Corporation of Los Angeles ("CMCLA"), the guarantors named therein and the
Trustee, by that certain Second Supplemental Indenture dated as of October 28,
1997 by and among CMCLA, the guarantors named therein and the Trustee, and by
that certain Third Supplemental Indenture dated as of August 23, 1999 by and
among CMCLA, the guarantors named therein and the Trustee (as so amended, the
"Indenture"), providing for the issuance of $200,000,000 aggregate principal
amount of 8-3/4% Senior Subordinated Notes due 2007 (the "Notes");

         WHEREAS, pursuant to that First Supplemental Indenture, dated as of
September 5, 1997, CMCLA assumed the obligations under the Notes and the
Indenture, and CMCLA and the Trustee amended certain other terms of the
Indenture;

         WHEREAS, pursuant to that certain Agreement and Plan of Merger by and
among CMCLA, Capstar Radio Broadcasting Partners, Inc., a Delaware corporation
("Capstar Radio"), SBI Holding Corporation, a Delaware corporation ("SBI"), and
the Company, dated as of November 19, 1999 (the "Merger Agreement"), among other
things, CMCLA, Capstar Radio, and SBI merged with and into the Company (the
"Merger");

         WHEREAS, the Company, the New Subsidiary Guarantors and the Trustee
desire by this Fourth Supplemental Indenture (i) pursuant to and as contemplated
by Section 5.01(a)(1)(B) of the Indenture, that the Company expressly assume all
of the obligations under the Notes and the Indenture, and (ii) pursuant to and
as contemplated by the provisions of the Indenture relating to the addition of
guarantors, including Sections 4.19, 9.01 and 10A.03, to add the New Subsidiary
Guarantors as guarantors pursuant to the terms of the Indenture;

         WHEREAS, the execution and delivery of this Fourth Supplemental
Indenture has been authorized by resolutions of the Boards of Directors of the
Company and each of the New Subsidiary Guarantors; and

         WHEREAS, all conditions and requirements necessary to make this Fourth
Supplemental Indenture a valid, binding legal instrument in accordance with its
terms have been performed and fulfilled by the parties hereto and the execution
and delivery thereof have been in all respects duly authorized by the parties
hereto.

         NOW, THEREFORE, in consideration of the above premises, each party
agrees, for the benefit of the others and for the equal and ratable benefit of
the holders of the Notes, as follows:



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                                    ARTICLE I

                       ASSUMPTION OF OBLIGATIONS AS ISSUER

         Section 1.01 ASSUMPTION. The Company hereby expressly and
unconditionally assumes each and every covenant, agreement and undertaking of
CMCLA under the Indenture as of the date of this Fourth Supplemental Indenture,
and also hereby expressly and unconditionally assumes each and every covenant,
agreement and undertaking of CMCLA under each Note outstanding on the date of
this Fourth Supplemental Indenture.

                                   ARTICLE II

                     ASSUMPTION OF OBLIGATIONS AS GUARANTOR

         Section 2.01 ASSUMPTION. Each of the New Subsidiary Guarantors hereby
expressly and unconditionally assumes each and every covenant, agreement and
undertaking of a Guarantor in the Indenture as of the date of this Fourth
Supplemental Indenture, and also hereby expressly and unconditionally assumes
each and every covenant, agreement and undertaking of a Guarantor in each Note
outstanding on the date of this Fourth Supplemental Indenture.

                                   ARTICLE III

                            MISCELLANEOUS PROVISIONS

         Section 3.01 DEFINED TERMS. For all purposes of this Fourth
Supplemental Indenture, except as otherwise defined or unless the context
otherwise requires, terms used in capitalized form in this Fourth Supplemental
Indenture and defined in the Indenture have the meanings specified in the
Indenture.

         Section 3.02 INDENTURE. Except as amended hereby, the Indenture and the
Notes are in all respects ratified and confirmed and all the terms shall remain
in full force and effect.

         Section 3.03 GOVERNING LAW. THIS FOURTH SUPPLEMENTAL INDENTURE SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK,
AS APPLIED TO CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW YORK, WITHOUT
REGARD TO PRINCIPLES OF CONFLICT OF LAWS.

         Section 3.04 SUCCESSORS. All agreements of the Company and the New
Subsidiary Guarantors in this Fourth Supplemental Indenture and the Notes shall
bind their successors. All agreements of the Trustee in this Fourth Supplemental
Indenture shall bind its successors.


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         Section 3.05 DUPLICATE ORIGINALS. All parties may sign any number of
copies of this Fourth Supplemental Indenture. Each signed copy shall be an
original, but all of them together shall represent the same agreement.

         Section 3.06 SEVERABILITY. In case any one or more of the provisions in
this Fourth Supplemental Indenture or in the Notes shall be held invalid,
illegal or unenforceable, in any respect for any reason, the validity, legality
and enforceability of any such provision in every other respect and of the
remaining provisions shall not in any way be affected or impaired thereby, it
being intended that all of the provisions hereof shall be enforceable to the
full extent permitted by law.

         Section 3.07 TRUSTEE DISCLAIMER. The Trustee accepts the amendment of
the Indenture effected by this Fourth Supplemental Indenture and agrees to
execute the trust created by the Indenture as hereby amended, but on the terms
and conditions set forth in the Indenture, including the terms and provisions
defining and limiting the liabilities and responsibilities of the Trustee, which
terms and provisions shall in like manner define and limit its liabilities and
responsibilities in the performance of the trust created by the Indenture as
hereby amended, and without limiting the generality of the foregoing, the
Trustee shall not be responsible in any manner whatsoever for or with respect to
any of the recitals or statements contained herein, all of which recitals or
statements are made solely by the Company and the New Subsidiary Guarantors, or
for or with respect to (i) the validity or sufficiency of this Fourth
Supplemental Indenture or any of the terms or provisions hereof, (ii) the proper
authorization hereof by the Company and the New Subsidiary Guarantors by
corporate action or otherwise, (iii) the due execution hereof by the Company and
the New Subsidiary Guarantors or (iv) the consequences (direct or indirect and
whether deliberate or inadvertent) of any amendment herein provided for, and the
Trustee makes no representation with respect to any such matters.

         Section 3.08 EFFECTIVENESS. This Fourth Supplemental Indenture shall
become effective, once executed, upon receipt by the Trustee of a certificate of
the appropriate officers of the Company; and an opinion of Vinson & Elkins
L.L.P., counsel to the Company, each of which shall be dated no earlier than the
date hereof.

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

                                      AMFM OPERATING INC.,
                                      as Obligor


                                      By: /s/ W. Schuyler Hansen
                                         --------------------------------------
                                         W. Schuyler Hansen
                                         Senior Vice President and Chief
                                           Accounting Officer

Attest:  /s/ Jean Menke
       -------------------------

                                      ON BEHALF OF EACH OF THE NEW SUBSIDIARY
                                      GUARANTORS LISTED ON SCHEDULE I HERETO*


                                      By: /s/ Kathy Archer
                                         --------------------------------------
                                         Kathy Archer
                                         Senior Vice President

Attest:  /s/ Jean Menke
       -------------------------

                                      U.S. TRUST COMPANY OF TEXAS, N.A.,
                                      as Trustee


                                       /s/ Bill Barber
                                      -----------------------------------------
                                      By:  Bill Barber
                                         --------------------------------------
                                      Title:  Vice President
                                            -----------------------------------

Attest:  /s/ Peg Makowski
       -------------------------




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

*For Capstar TX Limited Partnership, by Capstar Radio Operating Company, its
general partner.



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                                             CAPSTAR ROYALTY I CORPORATION
                                             CAPSTAR ROYALTY II CORPORATION
                                             CAPSTAR COMMUNICATIONS OF
                                               CALIFORNIA, INC.,
                                             as New Subsidiary Guarantors



                                             By:  /s/ Kathy Archer
                                                -------------------------------
                                                Kathy Archer
                                                President

Attest: /s/ Jean Menke
       -----------------------------



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                                   SCHEDULE I

                            NEW SUBSIDIARY GUARANTORS
            (ALL NEW SUBSIDIARY GUARANTORS ARE DELAWARE CORPORATIONS
                         EXCEPT AS EXPRESSLY INDICATED)


Chancellor Media Corporation of California
Chancellor Media Corporation of the Lone Star State
Chancellor Media Licensee Company
Chancellor Media Pennsylvania License Corp.
KZPS/KDGE License Corp.
Chancellor Marketing Group, Inc. (a Virginia corporation)
CBC Acquisition Company, Inc.
Capstar Acquisition Company, Inc.
Capstar Operating Corporation
Capstar Royalty II Corporation
Osborn Entertainment Enterprises Corporation
Music Hall Club, Inc. (a West Virginia corporation)
Jamboree in the Hills
Capstar Royalty I Corporation
Triathlon Broadcasting Company
Capstar Communications California, Inc.
Capstar Radio Operating Company
WPYX, Inc. (a New York corporation)
Capstar TX Limited Partnership (a Delaware limited partnership)