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.

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.

This series contains published annual calendars from three European organ builders.

The photographs in this series cover the several stages of the organ-building process. This series includes both colour and black-and-white images of the construction of a given organ at Wolff’s atelier, the installation of the organ, as well as concerts, dedications, and social events at or around the time of the organ’s installation.

The documents in this series include posters for concerts, several of which were given on Wolff’s instruments, as well as drawings and sketches of Wolff organs. These documents are not rolled like the organ plans in Series 1 but rather are spread flat

This series contains various temperament specifications.

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 various guides, rules and objects presumably used in the Wolff & Associés workshop.

This series contains French language reports prepared by the Ministère des Affaires culturelles du Québec, Direction régionale de Montréal, Direction du Patrimoine, by various authors. Each report is typescript and contains black and white photographs.

The maquettes in this series are various sizes of three-dimensional models of organs.