The Sonde Collection provides a thirty-five year span of documentation for a Montreal-based Canadian experimental musical group who were very active electroacoustic composers and performers in the 70s and 80s. Sonde (formerly named MUD, Musical Design), created and played sound sources in Quebec, Canada and Europe. Sonde’s compositions were generally conceived for live performance on original sound sculptures. Using meditative improvisation, the group produced new music with sounds created by electroacoustic amplification and transformation.
The Sonde Collection is divided into 26 series and contains approximately 1,900 items. The majority of the collection consists of correspondence, concert posters and programs, and audio and video recordings. Activities of the Sonde group are described together as Sonde Papers and the activities of Charles de Mestral, a founding member of the group as Charles de Mestral Papers.
In the Sonde Papers, whenever it has been possible to do so, each item is referenced to the events listing, a numbered, chronological listing of events created by the group, entitled: ACTIVITES DU GROUPE SONDE (1975-2010) / Sonde Activities (1975-2010). The Sonde Papers include posters, programmes, scores, photographs, audio and video recordings.
The Charles de Mestral Papers are the personal items of Charles de Mestral, a member of the Sonde group from its inception. Whenever it has been possible to do so, each item is referenced to the events listing entitled: RÉALISATIONS DANS LE DOMAINE DE L’INSTALLATION SONORE (1985-2013, Charles de Mestral) / Sound Installations (1985-2013, Charles de Mestral) a numbered, chronological list of activities of Charles de Mestral. The Charles de Mestral Papers include scores, correspondence, installation plans, clippings, audio recordings and publications.

Collection consists of Joseph Crawhall's correspondence, notes, memoranda, and manuscripts related to his research on engraver Thomas Bewick (1753-1828).

Collection consists of 59 heraldic plaques featuring Royal Navy and Royal Canadian Navy badges for ships and naval installations.

The fonds contains professional and private correspondence from Emma Albani, the first Canadian-born singer of international fame, to Parisian publisher Henri Heugel.

Fonds consists of an album of chiefly scenic postcards. Roughly half depict the western regions of Canada and the United States, including: Los Angeles, Pasadena, and San Francisco, California; Victoria and Vancouver, British Columbia; the Rockies; and Medicine Hat, Alberta. Other Canadian locations are represented including Ontario and Saskatchewan. European postcards make up roughly the second half of the postcards and are mostly from England, with some from Paris. A couple postcards feature cartoons or humourous scenes. One photographic postcard features kittens and there is one Christmas-themed postcard. Some of the postcards appear to have been sent between members of the Francis family of Headingley, Manitoba, including Lester Francis, Etta Francis, and Russel Francis.

Fonds consists of a typescript of "An archaeological expedition to the ruins of Southern Tunisia and the Sahara," 1924. This work includes articles by Louise de Forest Shelton, Arnold M. Duff, and Byron de Prorok.

This is a typescript copy of Maybury's diary, covering the period 1856 to 1875, and treating of life in colonial Australia, including a journey to the gold fields.

Fonds consists of Mackenzie's journal kept on Great Bear Lake.

This manuscript recounts the captivity of John Knubley, Master of the Mountezumar and Alexander Scott among the Moroccans after a ship wreck in 1810.