This series includes large-scale drawings, preliminary sketches, and general plans of various parts of the organ, such as the buffet, console, keyboards, and windchest. This series is divided into three subseries: organs with opus number; organs without opus number, which includes Wolff’s plans for proposed but ultimately not-constructed organs; and finally plans by other organ builders or Wolff’s drawings based on historical treatises and documents.

The photographic negatives are divided into three subseries: Wolff organs with opus number, Wolff organs without opus number, and non-Wolff organs.

This series contains Hellmuth Wolff’s correspondence files. Subseries i contains correspondence between Wolff and various organ builders in English, French and German, primarily related to Wolff’s editorial work for the for the International Society of Organbuilders’ ISO Yearbook 1993, which spanned four years from 1992-1996. Subseries ii contains workshop documents, including opus lists.

This series contains the print copies of journals and conference proceedings in Hellmuth Wolff’s library. There are some annotations on several of the issues. The works are listed in two separate bibliographies in Appendix 1: Periodicals/Journals Bibliography and Appendix 2: Conference Publications Bibliography.

This series contains seven recordings of organ music on Wolff organs.
Beauséjour, Luc (organist). Sonates bibliques = Biblical sonatas. Johann Kuhnau. CBC Records = Disques SRC MVCD 1086, 1996, compact disc.
Choir of the Church of St. John the Evangelist and Patrick Wedd (organist). A liturgical year: Alleluia psallat. Various composers. Church of St. John the Evangelist SJE CD0001, 1996, compact disc.
Fitzau, Jörn (organ builder). Organpipes. J. F. Organpipes, Promotional DVD from Taylor Fladgate.
Grew, John (organist). Livre d'orgue. Nicolas de Grigny. Outremont, Quebec: ATMA ACD 2 2169, 1998, compact disc.
MacDonald, David (organist). Journeys: Organ of Atlantic School of Theology. Various composers. CBC Radio Maritimes, 1997, compact disc.
Musique et tempérament [accord de l'orgue et du clavecin selon les tempéraments anciens]. Pierre-Yves Asselin, organ and Yannick Legaillard, harpsichord. Éditions Costallat MCE 9267-2, 1985, 2 cassettes.
Rousseau, Régis (organist). Johann Pachelbel. Johann Pachelbel. ATMA ACD 2 2173, 1998, compact disc.

This series contains a variety of photographs, correspondence and scrapbook items related to Donald Mackey and the Renaissance Singers. Notes on several items suggest that the owner of this material was Helen Mackey. Please see the Donald Mackey Collection and accompanying finding aid at http://www.mcgill.ca/library/find/subjects/music/special/donald-mackey-collection for related material.

Series consists of correspondence regarding collecting and general correspondence. Incoming correspondence to Geraldine Cole from booksellers, often with accompanying materials, friends, librarians, printers, and fellow collectors and book enthusiasts. Includes some correspondence from charitable organizations soliciting donations, including the Thomas Bewick Birthplace Appeal. Letters are mostly originals, with some printed emails. Consists primarily of incoming correspondence, with some drafts of outgoing correspondence. One file consists of substantial correspondence with John Borden, including many appended photocopied articles and book descriptions.

This series documents non-Catholic School Boards (Greater Montreal Protestant School especially) legal issues with language of instruction.

The Correspondence Series contains letters to or by Julius Schloss to the listed individual, except where noted. Additional correspondence pertaining to other series in the collection is listed below as well.