Duke Ellington, like Mozart before him and The Beatles during his later years, was always exploring the musical boundaries of his art form. And, like Mozart with his Gigue, and The Beatles with Revolution 9, he occasionally went way outside those boundaries.
Check out his piece The Clothed Woman, from 1947:
Ellington's avant garde piano playing on The Clothed Woman predates similar playing by Cecil Taylor and Lennie Tristano.
[…] The avant garde side of Duke Ellington […]