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 Programmes and Scripts series contains programmes of Donald Mackey and the Church of Messiah and the Renaissance Singers of Montreal in performance; as well as scripts and programming for the following series presented/performed by the Renaissance Singers: CBC broadcasts not in a series, Christian Frontiers, Sunday Chorale and Good Friday.

The Scores series contains copies of various scores of works performed by the Renaissance Singers of Montreal. Additional information provided where possible.

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.