Joseph Gould was an important figure in the musical life of late nineteenth-century Montreal. His activities as a church musician, piano and organ dealer, and journalist made a considerable impact on artistic life in the city. But it was as the founder and conductor of the Montreal Mendelssohn Choir that Gould's influence was most keenly felt. Founded in 1864, the Mendelssohn Choir enjoyed a thirty-year lifespan and became famous for its high standard of performance. The library of the Choir, housed at the Marvin Duchow Music Library of McGill University, is an important collection, not only because of the presence of a number of interesting pieces of Canadiana within it, but as a basis for further study of nineteenth-century choral music. Included in this thesis is a catalogue of this collection as well as a list of Gould's known compositions.