The Morton Feldman Papers comprise personal and business correspondence, writings by and about Feldman, clippings, programs, and photographs.

The collection contains recordings of fifty-one of the fifty-three concerts presented at the June in Buffalo festival from 1975-1978 and in 1980. Approximately 216 works were recorded as well as some spoken introductions to works by their respective composers. The collection also contains recordings of three of the five lecture-seminars presented by John Cage during June in Buffalo 1975.

The collection of Slee Lecture Recital Recordings contains 94 reel to reel tapes of lectures by the named Slee Visiting Lecturer in the Music Department at the State University of New York at Buffalo.