The Gilbert Trythall Collection encompasses work from Trythall's career as a composer and professor. The collection includes a range of materials including scores, books, photographs, tapes, and audio reels. The collection also includes many programs and promotional materials from the Electronic Music Plus Festival, a festival founded by Trythall and hosted at universities across the United States.

Series I: Research, Scores, and Teaching, 1948-1998, undated. This series contains scores, performance instructions, concert programs, academic materials, and media materials associated with Trythall and the Electronic Music Plus Festival. Scores and Materials (Subseries A) contains many of Trythall's compositions as well as copyright requests, text copies, and compositional notes. Performance Instructions and Materials (Subseries B) detail the specifics of works with no score extant in the series. Photographs (Subseries C) features images ofTrythall, fellow musicians, and music technology. Other Research, Scores, and Teaching (Subseries D) consists of media clippings and academic materials associated with Trythall. Programs (Subseries E) includes programs and promotional materials for the first eighteen Electronic Music Plus Festivals and programs from other concerts in which Trythall was the composer or conductor. Books (Subseries F) includes Trythall's book and textbooks written during his time as a professor.

Series II: Media and Recordings, 1957-1999, undated. This series contains an assortment of audio recordings on different mediums. Cassettes (Subseries A), VHS (Subseries B), Audio Reels (Subseries C), Vinyl (Subseries D), and Oversized Audio Reels (Subseries E) each contain recordings of compositions by Trythall and others performed by various individuals and groups. This material is arranged first by format and then alphabetically by title of piece.

Series III: Oversized Scores, 1954-1970, undated. This series includes oversized scores and parts for Trythall's original compositions. Many of the parts have hand-written markings and notes.