Papineau-Couture returned to Montreal and became a transformative force in Canadian music education.
He became a professor, later serving as Dean of the Faculty of Music at he Université de Montréal (1967–1973) and helped modernize the curriculum and elevate the institution to international standing. He mentored a generation of influential Canadian composers, including François Morel, Gilles Tremblay, and Serge Garant (a key figure in Société de musique contemporaine du Québec).
Papineau-Couture was also a co-founder and early supporter of the Canadian League of Composers and played an important leadership role in the development of contemporary music societies across Quebec and Canada.
Some of his most admired compositions include "Psaume CL” (1952), for choir, deeply rooted in sacred tradition but modern in texture; "Étude IX”, a hallmark of his interest in instrumental clarity; "Dialogue” (for various instrumentations); "Fantaisie” for piano; "Symphonietta”, one of his most performed orchestral works, and "Pièces concertantes” – showing his lyrical side within a modernist vocabulary. His catalogue spans solo works, chamber music, choral compositions, orchestral works, and vocal pieces.
He received the Officer of the Order of Canada (1978), Companion of the Order of Canada (1991), Prix Denise-Pelletier (1981),
and the Grand Prix du Conseil des arts de Montréal. The Jean-Papineau-Couture Prize named in his honor (awarded to emerging composers).
Jean Papineau-Couture helped lay the foundation for modern Canadian composition. His work as a composer, pedagogue, and cultural leader left a lasting imprint on Quebec’s artistic identity and shaped several generations of Canada’s musical creators.