<PAGE>   1

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-K
                                    ---------

                ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 1998                         Commission file
                                                                number 2-22997
                                                                --------------

                                MILLS MUSIC TRUST
--------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)

               New York                               13-6183792
--------------------------------------------------------------------------------
    (State or other jurisdiction of               (I.R.S. Employer
     incorporation or organization)               Identification No.)

        c/o Marine Midland Bank, N.A., 140 Broadway, New York, NY 10005
--------------------------------------------------------------------------------
        (Address of principal executive offices)               (Zip code)

Registrant's telephone number, including area code  (212) 658-6014
--------------------------------------------------------------------------------

Securities Registered Pursuant to Section 12(b) of the Act:

                                      NONE
--------------------------------------------------------------------------------
                                (Title of Class)

Securities Registered Pursuant to Section 12(g) of the Act:

                          UNITS OF BENEFICIAL INTEREST
--------------------------------------------------------------------------------
                                (Title of Class)

      Indicate by check-mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such report), and (2) has been subject to such
filing requirements for at least the past 90 days.

                                    YES X NO

      As of March 4, 1999, 277,712 Trust Units were outstanding. The aggregate
market value of the Units of Mills Music Trust held by nonaffiliates was
$11,177,988.

                       DOCUMENTS INCORPORATED BY REFERENCE
                                      NONE

                                     PART I
<PAGE>   2

                                                                               2


Item 1. Business.

      Mills Music Trust (the "Trust") was created by a Declaration of Trust
dated December 3, 1964, for the purpose of acquiring from Mills Music, Inc.
("Old Mills") the rights to receive payments of a deferred contingent purchase
price obligation payable to Old Mills. The purchase price obligation arose as
the result of the sale by Old Mills of its musical copyright catalogue to a
newly formed company ("New Mills").

      In payment for the aforementioned catalogue, New Mills agreed to make
quarterly payments to Old Mills (the "Contingent Portion") measured by the
royalty income generated from the catalogue and, subject to certain limitations
and conditions, from any copyrights thereafter acquired by New Mills.

      The contingent Portion for each quarterly period to and including the last
quarter of 2009 is to be an amount equal to the excess, if any, of (a) the gross
royalty income from the exploitation of the purchased copyrights during such
period (whether received by New Mills, its affiliated companies or any other
party) over (b) the sum of (i) the greater of (x) 25% of such gross royalty
income or (y) the lesser of $87,500 (as adjusted for inflation by reflecting
changes in average weekly earnings of employees in the printing, publishing and
allied industries since 1964) or 30% of such gross royalty income; and (ii)
royalties required to be paid to composers, authors and others with respect to
the existing copyrights. If the Contingent Portion as so computed is less than
$167,500, then the Contingent Portion will be computed on the basis of the gross
royalty income and related expense of New Mills, its affiliated companies and
their successors and assigns during such period not only from the exploitation
of purchased copyrights, but also from any copyrights originated or acquired by
New Mills and its affiliated companies subsequent to December 5, 1964 (with the
deductions referred to in (i) and (ii) above) except that, when computed in this
manner, the Contingent Portion cannot exceed $167,500. In addition, for any
quarterly period in which the contingent portion as calculated above exceeds
$250,000, the percentage specified in (x) above is increased to as high as 35%
based upon gross royalties for the quarter.

      Commencing with the first quarter of the year 2010, the Contingent Portion
for each quarterly period is to be an amount equal to 75% of the gross royalty
income of New Mills and/or its affiliated companies and their successors and
assigns from the exploitation of the existing copyrights for such period, less
the related royalty expense.
<PAGE>   3

                                                                               3


      The acquisition purchase agreement provides that the obligation to make
payments will terminate on the last day of the year in which the last purchased
copyright, or a renewal thereof, expires and cannot be renewed. When the
existing copyrights begin to expire, the size of each payment through the year
2009 will become increasingly dependent on the success which New Mills has in
renewing the copyrights.

      The composition of Old Mills Catalogue is estimated to be in the excess of
25,000 titles of which approximately 1,500 are at present producing royalty
income. The major portion of the royalty income generated by the catalogue in
recent years, however, was produced by a relatively small number of well-known
songs, many of which have remained popular and have generated substantial
royalty income over a long period.

      The Declaration of Trust prohibits the Trust from engaging in any
business; the Trust's sole activity is the receipt of the periodic installments
of the purchase price and the distribution thereof, (after payment of expenses
of the Trust) to the owners of units of beneficial interest in the Trust.

ITEM 2. Properties.

      The administrative office of the Mills Music Trust is at 140 Broadway, New
York, New York 10005. There is no expense being charged or paid for office space
and office equipment being utilized by the Trust.

ITEM 3. Legal Proceedings

      NONE

ITEM 4. Submission of Matters to a Vote of Security Holders.

      NONE
<PAGE>   4

                                                                               4


                                     PART II

ITEM 5. Is not applicable.

ITEM 6. Selected Financial Data.

The following selected financial data for the years ended December 31, 1998
through 1994 are derived from the trust's audited financial statements. The data
set forth below should be read in connection with financial statements of the
trust and the notes thereto and "management discussions and analysis" appearing
elsewhere herein.

<TABLE>
<CAPTION>
                                              Cash            Cash
       Year Ended     Receipts From      Distributions    Distribution
      December 31,  Mills Music, Inc.   To Unit Holders     Per Unit*
      ------------  -----------------   ---------------   -------------
<S>      <C>           <C>                   <C>              <C>  
         1998          $1,035,853            $999,734         $3.60
         1997          $1,137,919          $1,101,434         $3.97
         1996          $1,175,543          $1,148,285         $4.13
         1995          $1,268,400          $1,227,155         $4.42
         1994          $1,308,116          $1,269,515         $4.57
</TABLE>

* Based on the 277,712 Trust Units outstanding

ITEM 7. Management's Discussion and Analysis of the Trust's Receipts.

      The Trust's receipts are derived principally from copyrights established
prior to 1964 and such receipts fluctuate based upon public interest in the
"nostalgia" appeal of older copyrighted songs.

ITEM 8. Financial Statements.

      The financial statements begin on page 5 of this report.
<PAGE>   5

                     [LETTERHEAD OF DAVID BERDON & CO. LLP]

                          INDEPENDENT AUDITORS' REPORT

The Trustees and Unit Owners
Mills Music Trust

We have audited the accompanying statement of cash receipts and disbursements of
Mills Music Trust for the year ended December 31, 1998. This financial statement
is the responsibility of the Trust's management. Our responsibility is to
express an opinion on this financial statement based on our audit.

We conducted our audit in accordance with generally accepted auditing standards.
Those standards require that we plan and perform the audit to obtain reasonable
assurance about whether the financial statement is free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amount and disclosures in the financial statement. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audit provides a reasonable basis for our opinion.

As described in Note 1, this financial statement was prepared on the basis of
cash receipts and disbursements, which is a comprehensive basis of accounting
other than generally accepted accounting principles.

In our opinion, the financial statement referred to above presents fairly, in
all material respects, the cash receipts and disbursements of Mills Trust for
the year ended December 31, 1998, on the basis of accounting described in Note
1.


                                                    /s/ David Berdon & Co. LLP
                                                    Certified Public Accountants

March 23, 1999
<PAGE>   6

                              [LETTERHEAD OF KPMG]

                          INDEPENDENT AUDITORS' REPORT

The Trustees and Unit Owners
Mills Music Trust:

We have audited the accompanying statement of cash receipts and disbursements of
Mills Music Trust for each of the years in the two year period ended December
31, 1997. These financial statements are the responsibility of the Trust's
management. Our responsibility is to express an opinion on this financial
statement based on our audits.

We conducted our audit in accordance with generally accepted auditing standards.
Those standards require that we plan and perform the audit to obtain reasonable
assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

As described in Note 1, these financial statements were prepared on the basis of
cash receipts and disbursements, which is a comprehensive basis of accounting
other than generally accepted accounting principles.

In our opinion, the financial statements referred to above presents fairly, in
all material respects, the cash receipts and disbursements of Mills Trust for
each of the years in the two-year period ended December 31, 1997, on the basis
of accounting described in Note 1.


                                                            KPMG LLP
                                                          /s/ KPMG LLP

March 19, 1998
New York, New York
<PAGE>   7

                                                                               5


                                MILLS MUSIC TRUST
                  STATEMENTS OF CASH RECEIPTS AND DISBURSEMENTS
                             YEARS ENDED DECEMBER 31

<TABLE>
<CAPTION>
                                         1998            1997           1996
                                         ----            ----           ----
<S>                                   <C>             <C>            <C>       
Receipts from Mills Music, Inc.       $1,035,853      $1,137,919     $1,175,543

                                     -----------     -----------    -----------
   Total Receipts                     $1,035,853      $1,137,919     $1,175,543

Undistributed Cash at Beginning                8              21             30
   of Year

Disbursements -
   Administrative Expenses           (    36,117)     (   36,498)     (  27,267)
                                     -----------     -----------    -----------
Balance Available for Distribution       999,744       1,101,442      1,148,306

Cash Distributions to Unit Holders   (   999,705)     (1,101,434)    (1,148,285)
                                     -----------     -----------    -----------
Undistributed Cash at
   End of the year                   $        39     $         8     $       21
                                     -----------     -----------    -----------
Cash Distributions Per Unit
 (based on the 277,712
  Trust Units Outstanding)           $      3.60     $      3.97     $     4.13
                                     ===========     ===========    ===========
</TABLE>

      The Trust does not prepare a balance sheet or a statement of cash flows.
     
     See accompanying Notes to Statements of Cash Receipts and Disbursements.
      
<PAGE>   8

                                                                               6


                                MILLS MUSIC TRUST
             NOTES TO STATEMENTS OF CASH RECEIPTS AND DISBURSEMENTS

Note 1. Accounting Policies and General Information.

      Mills Music Trust (the "Trust") was created in 1964 for the purpose of
acquiring the rights to receive payment of a deferred contingent purchase price
contract obligation payable by Mills Music, Inc. ("Mills"). The contingent
payments are determined quarterly and are based on a formula which takes into
account gross royalty income paid to composers, authors and others, and less
amounts deducted by Mills in accordance with contract terms.

      Payments from Mills to the Trust are made in March, June, September and
December and include net royalty income of the preceding calendar quarter. The
payments received are accounted for on a cash basis, as are expenses. The
Declaration of Trust requires the distribution of all funds received by the
Trust to the unit holders after payment of expenses.

      The statements of cash receipts and disbursements reflect only cash
transactions and do not present transactions that would be included in financial
statements presented on the accrual basis of accounting, as contemplated by
generally accepted accounting principles.

Note 2. Federal Income Taxes

      No provision for income taxes has been made since the liability therefore
is that of the unit holders and not the Trust.

Note 3. Related Party Transactions

      The Declaration of Trust provides that each trustee shall receive annual
compensation of $2,500 per year for services as trustee, provided that such
aggregate compensation to the trustees as a group may not exceed 3% of the
monies received by the Trust in any year, and reimbursement for expenses
reasonably incurred in the performance of their duties. The Declaration of Trust
further provides for reimbursement to the corporate trustee for its clerical and
administrative services to the Trust. Accordingly, Marine Midland Bank, the
corporate trustee, also receives reimbursement for such services (including
services performed as Registrar and Transfer Agent of the Certificates
representing Units). The Declaration of Trust also provides, that if in the
future any trustee performs unusual or extraordinary services, reasonable
compensation for such services shall be paid, subject to certain limitations and
to prior confirmation by a majority in interest of Trust Certificate holders.
<PAGE>   9

                                                                               7


                                MILLS MUSIC TRUST
        NOTE TO STATEMENTS OF CASH RECEIPTS AND DISBURSEMENTS (CONTINUED)

Note 3. Related Party Transactions (continued).

      Pursuant to these provisions, disbursements were made as follows for the
years ended December 31:

<TABLE>
<CAPTION>
Trustees                              1998       1997        1996
--------                            -------    -------     -------
<S>                                 <C>        <C>         <C>    
  Marine Midland Bank               $ 2,500    $ 2,500     $ 2,500
  Bernard Fischman                    2,500      2,500       2,500

Marine Midland Bank as registrar
 and transfer agent                   5,839      5,932       - 0 -
</TABLE>

Note 4. Royalty Examination

      The Trust has determined that its previously disclosed claim against the
former administrator of the Old Mills Catalogue in connection with the 1987
royalty examination is not cost beneficial and, therefore, is not being pursued.
No examination of royalty information has been performed subsequent to 1987.

Note 5. Year 2000 Computer Readiness

      Due to the limited number of transactions the Trustees believe their would
be no significant impact for year 2000 computer readiness on the operations of
the Trust.

ITEM 9. Is not applicable.
<PAGE>   10

                                                                               8


                                    PART III

ITEM 10. Directors of the Registrant.

      Bernard D. Fischman is the individual Trustee and Marine Midland Bank is
the Corporate Trustee of the Registrant. The Trustees serve until their removal,
resignation, incapacity, or in the case of individual Trustees, their death.

      Mr. Fischman, age 84, has served as a trustee since December, 1964. He is
an attorney and a member of the firm of LeBoeuf, Lamb, Green & McRae.

      Marine Midland Bank, N.A. has been the corporate trustee since February,
1965 and is a national banking association organized under the laws of the
Unites States.

ITEM 11. Executive Compensation. See Item 13.

ITEM 12. Security Ownership of Certain Beneficial Owners and Management.

(a) Security Ownership of Certain Beneficial Owners.

      To the best knowledge of the Trustees, the only persons who beneficially
own more than 5% of the Trust Units are as follows:

<TABLE>
<CAPTION>
                                                                     Percent
Name and Address of                         Number of                of Units
Beneficial Owner                            Units Owned             Outstanding
------------------------                    -----------             -----------

<S>                                        <C>                        <C>
MPL Communications, Ltd.
39 West 54th Street
New York, New York 10019                    79,609 Units              28.67%

Cede & Co.
Fast Cod Balance
P.O. Box 20
Bowling Green Station
New York, New York 10004                   136,470 Units              49.14%
</TABLE>
<PAGE>   11

                                                                               9


(b) Security Ownership of Management.

      The present Trustees have beneficial ownership in the Trust as follows:

<TABLE>
<CAPTION>
                                            Nature of            Percentage
                                            Beneficial           of Units
   Trustee                                  Ownership            Outstanding
   -------                                  ----------           -----------
<S>                                         <C>                     <C> 
Bernard D. Fischman                         351 Units               .13%
                                            (Sole Owner)

Marine Midland Bank                         None                    None
</TABLE>

(c) Changes in Control.

      The Trustees know of no contractual arrangements which may result in a
change in control of the Trust at a subsequent date.

ITEM 13. Certain Relationships and Related Transactions.

      Remunerations of Directors and Officers.

      The Declaration of Trust provides that each trustee shall receive annual
compensation of $2,500 per year for his services as trustee, provided that such
aggregate compensation to the trustees as a group may not exceed 3% of the
monies received by the Trust in any year, and reimbursement for expenses
reasonably incurred in the performance of his duties. The Declaration of Trust
further provides for reimbursement to the corporate trustee for its clerical and
administrative services to the Trust. Accordingly, Marine Midland Bank also
receives reimbursement for such services (including services performed as
Registrar and Transfer Agent of the Certificates representing Units). The
Declaration of Trust further provides that if in the future any trustee performs
unusual or extraordinary services, reasonable compensation for such services
shall be paid, subject to certain limitations and to prior confirmation by a
majority in interest of Trust Certificate holders. During 1996, pursuant to
these provisions, Bernard D. Fischman received $2,500 and Marine Midland Bank
$2,500.
<PAGE>   12

                                                                              10


                                     PART IV

ITEM 14. Exhibits, Financial Statements Schedules and Reports on Form 8-K

(a) 1.   Financial Statements                                               Page
                                                                            ----

Independent Auditors' Reports                                               5-5A

Statements of cash receipts and disbursements -
  years ended December 31, 1998, 1997 and 1996                                 6

Notes to statements of cash receipts and disbursements.                     7-8

     2.   Financial Statement Schedules                                     None

     3.   Exhibits                                                          None

(b) Reports on Form 8-K                                                       11
<PAGE>   13

                                                                              11


                                MILLS MUSIC TRUST

                                     FORM 8K

Item 4. Changes in Registrant's Certifying Accountant

(a)(1)(i)      On March 4, 1999 the registrant terminated KPMG LLP (KPMG) as its
               principal auditors.

(a)(1)(ii)     The reports of KPMG on the financial statements for the past two
               years did not contain a disclaimer of opinion or an opinion that
               was adverse or was qualified or modified for uncertainty, audit
               scope, or accounting principle.

(a)(1)(iii)    The decision to change auditors was recommended and approved by
               the Trustees.

(a)(1)(iv)     During the two most recent fiscal years and any subsequent
               interim period preceeding this dismissal, there were no
               disagreements with KPMG on matters of accounting principle or
               practice, financial statement disclosure, or audit scope or
               procedures that, if not resolved to their satisfaction, would
               have caused KPMG to refer to the subject matter of the
               disagreements in their report.

(a)(2)         On March 5, 1999 the registrant engaged David Berdon & Co. LLP as
               its principal auditors.

                                   SIGNATURES

      Pursuant to the requirement of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                                       MILLS MUSIC TRUST
                                               ---------------------------------
                                                          (Registrant)


Dated as of March 18, 1999                     By: BERNARD D. FISCHMAN
                                                   -----------------------------
                                                   Bernard D. Fischman, Trustee
<PAGE>   14

                              [LETTERHEAD OF KPMG]

Securities and Exchange Commission                                March 30, 1999
Washington, D.C. 20549

Ladies and Gentlemen:

We were previously principal accountants for Mills Music Trust and, under the
date of March 19, 1998, we reported on the statements of cash receipts and
disbursements of Mills Music for each of the years in the three-year period
ended December 31, 1997. On March 4, 1999, our appointment as principal
accountants was terminated. We have read Mills Music Trust's statements included
under Item 4 of its Form 8-K dated March 30, 1999, and we agree with such
statements.

Very truly yours,


/s/ KPMG LLP
<PAGE>   15

                                                                              12


                                   SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.


                                                      MILLS MUSIC TRUST
                                                --------------------------------
                                                         (Registrant)


                                                By: BERNARD D. FISCHMAN
                                                    ----------------------------
                                                    Bernard D. Fischman, Trustee


                                                By: MARINE MIDLAND BANK
                                                    ----------------------------
                                                    Marine Midland Bank
                                                    Corporate Trustee

Dated as of March 18, 1999

      Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
registrant and in the capacities and on the dates indicated.