 Appointed assistant to Zubin Mehta, the MSO's artistic director, Hétu was responsible for conducting the Matinées symphoniques; he held the position until 1968.He premiered André Prévost's Fantasmes in November 1963 with the MSO and Maurice Dela'sProjection in 1967.He also conducted Prévost's Terre des hommes during the opening of the World Festival of Expo 67.