He has served on the faculty of the Juilliard School since 1998, but has long been associated with the Mannes College of Music where he has been affiliated with the Techniques of Music faculty since 1956; Chairman of Theory Department, 1958–1962; Dean of Mannes, 1962–1966; Chairman of Techniques of Music Department 1966–1973.
Působil na fakultě Juilliard School od roku 1998, ale byl stále spojen s Mannes College of Music, kde pracoval na fakultě Techniky hudby už od roku 1956; ředitel oddělení teorie, 1958-1962; Dean of Mannes, 1962-1966; ředitel techniky hudby 1966-1973.