A composer, pianist, theorist and teacher, Henry Cowell was an important musical innovator who sythesized Western, Asian and African music in an effort to create an "ultramodern" style. Some of his students included John Cage, George Gershwin, and Burt Bacharach.
His piano composition "The Tides of Manaunaun was the first to include tone clusters; this requires adjacent notes to sound simultaneously, requiring the keys be struck with the arm or hand. His "Aeolian Harp" was one of his first pieces which required performers to manipulate the strings of a piano directly.
His career was damaged at the age of 39 when he was arrested and imprisoned for 15 years at San Quentin State Prison for having sex with a 17 year old male. In prison, he taught inmates music, directed the prison band and continually and prolifically wrote music.
In the Ritournelle (Larghetto and Trio) (1939) for the dance piece Marriage at the Eiffel Tower, Cowell explored what he termed an "elastic" form. The twenty-four measures of the Larghetto and the eight of the Trio are each modular. Cowell offers some suggestions as to how these are to be performed, but he creates freedom in the piece. Any of the measures may be included or not and played once or repeatedly, allowing the piece to stretch or contract at the performers' will. The goal is to allow a choreographer the freedom to sculpt the dance piece uniquely. There were none of the usual constraints imposed by a prewritten musical composition.
In 1940 Cowell was paroled and eventually granted a pardon two years later. His friends maintain that Cowell lost his mastery after having been imprisoned, leading to a steady decline in the quality of his work.