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.

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.