The Administration Materials series contains documentation pertaining to the management and chronology of the Renaissance Singers of Montreal.

The Photographs series contains photographs of church organs, professional photos of Donald Mackey alone and with others. Also includes correspondence from Helen Mackey to Cynthia Leive.

The Concert Programmes series contains programmes of concerts performed and/or attended by Donald Mackey. The series is organized chronologically, by subject as indicated.

The Scripts and Writings series contains writings, lectures and talks by Donald Mackey; as well as documentation pertaining to special projects organized and carried out by Donald Mackey (i.e. organ installations and events). The series is organized chronologically.

The Biographical Information series contains divergent materials, all relating to Donald Mackey’s personal or professional life. The series includes his thesis and writings, lectures, and other miscellaneous personal documents. The series is arranged chronologically by time period as indicated.

The Compositions series contains sketches, texts and manuscripts of 30 of Kelsey Jones’ major compositions. The works are arranged chronologically. Composition dates, durations and instrumentations are provided when possible.

The Biographical Information series contains correspondence, programmes and a photograph of Kelsey Jones. The series consists of cards and letters to or from Kelsey Jones; as well as a selected of programs he found interesting. The series is arranged chronologically, and are divided by subject headings (the subject headings chosen for this section were indicated by Kelsey Jones himself). The series includes correspondence of special note to/from Lord Beaverbrook, John Beckwith, Marvin Duchow, Herman Geiger-Torel, Harold Hamer, Leonard Isaacs, George Johnston, George Little, Ernest MacMillan and Healy Willan.

The Photographs Series contains autographed photographs of Alban Berg, Fritz Heinrich Klein, and Bernhard Sekles, as well as photographs of Julius Schloss. Additional photographs printed in other series of the collection are listed below as well.

The Clippings Series contains articles and clippings from newspapers, magazines and journals that pertain to people, music, and specific periods of Schloss’s life. Items are arranged topically.