The Canadian conductor, organist, harpsichordist and teacher, Mireille Lagacé (born: Bégin), studied in Montreal with Germaine Malépart (piano), Conrad Letendre (organ), and Gabriel Cusson (theory). She went to Austria in 1956 on a Quebec government scholarship and studied organ with Anton Heiller. Returning to Montreal in 1962, she continued her organ and harpsichord studies from 1957 to 1962 with her husband, Bernard Lagacé, and took part in the activities of the group Ars Organi. In 1959 she was awarded a first prize at the Organ Competition of the Montreal Centre of the RCCO (John-Robb Organ Competition). In 1962, she was a prize winner at the Munich and Geneva International Organ Competitions, and in 1965, she was a harpsichord finalist at the Geneva International Competition.
In 1964 Mireille Lagacé founded the Ensemble Couperin-le-Grand. She is one of the most sought after artists on the international music scene, and is one of the rare performers to be equally at ease on the organ and the harpsichord. She has pursued a busy career as a soloist and chamber player in Canada, the USA, and western Europe. She has always distinguished herself by her brilliant technique, as well as for the perfection, sensibility and vitality of her performances. She began to perform on the fortepiano in 1988. Some works have been dedicated to her, including Jean Papineau-Couture's Dyarchie which she premiered in 1971 in Boston, and Jean Lesage's Thanatopsis (1981). In 1977 she was chosen for a Victor M. Lynch-Staunton Award by the Canada Council. In 1978 she recorded a considerable portion of Bach's complete works for harpsichord for Calliope. The day following her performance of the Goldberg Variations (BWV 988) at the Erskine and American Church, Carol Bergeron commented in Montreal's Le Devoir (October 16, 1989): 'A superb and moving musician, an exceptional harpsichordist, Mireille Lagacé performed this formidable and monumental score with the serene assurance of an artist who has long since matured her interpretation.'
To complement her activities as soloist and chamber musician, Mireille Lagacé enjoys a very active pedagogical career. She taught harpsichord at the University of Montreal from 1967 to 1972 and organ at the New England Conservatory in Boston from 1970 to 1980. In 1973 she began teaching harpsichord and Baroque music at the Conservatoire de musique du Québec in à Montréal (CMM). During the summers she has taught baroque music from 1964 to 1974 at the Canadian Amateur Musicians/Musiciens amateurs du Canada (CAMMAC) music centre, and harpsichord from 1974 to 1980 at the JMC Orford Art Centre, from 1970 to 1980 at the Choate Music Seminars in Wallingford, Connecticut, and from 1980 at the Académie d'orgue de St-Dié, in France. She was invited to give numerous master-classes in the United States, Canada and Europe.