He has directed concerts and recordings for television specials, and was choral director for a television special and recording starring Jessye Norman and Kathleen Battle, conducted by James Levine.
De Cormier was the conductor and leader of The Belafonte Folk Singers during most of its lifetime from 1957 to 1965. He also headed The Robert De Cormier singers, who performed extensively in the mid-1960s and then on and off until the mid-1990s
Robert De Cormier was Music Director and Conductor of the New York Choral Society from 1970–1987 and is a Music Director Emeritus. In 1993, De Cormier helped to found the Vermont Symphony Orchestra Chorus, and remains its director.