A pioneer of avant-garde music in America, Henry Cowell (1897-1965) was the son of writers in rural California who fell in with futurists and theosophists early in his career, producing works that explored atonality, polytonality, aleatory music, and nontraditional techniques. In 1936, Cowell was imprisoned on a morals charge after admitting to engaging in sex acts with multiple teenage boys. He spent four years in prison, and despite receiving a presidential pardon in 1942, his music became steadily more conservative and declined in quality after that.