Bennett studied with Busch in Kansas City and with Boulanger in Paris. He composed a wide variety of music, including several symphonies and orchestral works, music for chamber groups and wind bands, two operas and a ballet-opera. However, Bennett's recognition stems from his work in orchestration. This career started with a commission in 1919 by the publishers T.B. Harms to orchestrate songs for the theatre. One of his earliest efforts was Cole Porter's An Old Fashioned Garden (1919). He went on to become the leading orchestrator for Broadway musicals from the 1920s to the 60s.