The collection contains 172 original reel to reel tape recordings of 113 recitals containing approximately 613 works. The works range from the Renaissance to music created for the concerts, even improvised at the events. The reels are accompanied by audio cassette recordings created as service copies and a hard drive containing digitally reformatted preservation and access files.

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.