Bennett wrote over two hundred works for the concert hall, and fifty scores for film and television. He also wrote and performed jazz songs. In the 1950s he studied in Paris with Pierre Boulez who encouraged him to write serial music, but later his music became more tonal and easier to listen to. He wrote jazz music, film music and concert music for the BBC Proms and the Three Choirs Festival. In 1976 he wrote "Zodiac" for the National Symphony Orchestra of Washington to celebrate the bicentenary of the United States of America. He dedicated the work to Elisabeth Lutyens. He started to give up serialism and combined various musical techniques to create his own personal style. In 1979 he moved to the United States.