The Alexander Semmler Papers contain music written by Alexander Semmler, both published and unpublished, as well as some of his notes and correspondence.

Collection of 125 complete pieces of sheet music from European countries: Austria (5), Belgium (6), England (54), France (9), Germany (31), Italy (14), and the Netherlands (5). Most of these include title page illustrations, about 30 of which are in color. The collection includes an additional 24 partial works, most of which consist only of their title pages. The musical content consists of 44 works for solo piano and approximately 75 works for some combination of voice and piano.

Collection of 92 pieces of sheet music, chiefly from the United States, most with title page illustrations.

Frederick Werlé (1910-1997) was a composer, music teacher, and a former dean of the Mannes College of Music. His papers primarily consist of reel-to-reel and LP audio recordings and original music manuscripts. Also present in the collection are newspaper clippings, published music scores, concert programs, correspondence and notes.

The collection contains scores and parts of twenty original compositions by Friedrich Otto Trautmann, a composer and organist who lived in Germany and England in the late nineteenth to early twentieth century.

Leopold Mannes (1899-1964) was an American musician, educator, inventor, and son of the founders of the Mannes School of Music, David and Clara (Damrosch) Mannes. Leopold Mannes and Leopold Godowsky, Jr. invented Kodachrome color photography. Mannes became president of the Mannes School of Music in 1948. This collection contains music manuscripts of Mannes's compositions, including arrangements of pieces by other composers.

Thirty-five titles of sheet music related to the 1901 Pan-American Exposition in Buffalo and one title related to an exposition held in 1905 in Buffalo. All but nine of the titles are photocopies of works in the Buffalo & Erie County Public Library.

The collection contains approximately 1300 scores, half of which bear markings entered by Mikhashoff or his colleagues in preparation for performance. The collection includes manuscripts and print publications, both originals and reproductions.

The collection contains 249 cassettes featuring performances either by Mikhashoff or of his music, 801 non-commercial cassettes and 115 commercially-released cassettes that do not contain performances or works by Mikhashoff.

The collection contains 155 reel to reel tapes featuring performances either by Mikhashoff or of his music, 31 reels that do not contain performances or works by Mikhashoff, and 19 reels containing tape parts to accompany performances. Five LP sound recordings and nine compact discs are also included in the collection.