The collection consists of correspondence, diaries, and writing and music material created and collected during Sitsky's long and productive career as a composer, musicologist, pianist, teacher and writer. The correspondence includes letters and emails to and from composers such as Felix Werder, Nigel Butterley, Richard Meale, Colin Brumby, Ann Carr-Boyd, Vincent Plush, James Penberthy, Elena Kats-Chernin, George Dreyfus and Miriam Hyde. Sitsky also corresponded with musicians and his publishers, and over a long period with poet and librettist Gwen Harwood. The music component of the collection includes composition diaries, pencil and ink scores and published works by Sitsky as well as pieces by Roy Agnew and other Australian composers.