Which early band leader was also a prolific composer?

Duke Ellington was an early band leader who was also a prolific composer. He was a leader of a jazz orchestra back in the early 20th century until his death in 1974. Apart from being a pianist and leader of this band, he was also a composer who prided himself on many popular compositions he wrote for the band and some other projects.

Chicken breast with a green salad in a serving of vegetables