Hyman Paul Bley, CM (November 10, 1932 – January 3, 2016) was a Canadian pianist known for his contributions to the free jazz movement of the 1960s as well as his innovations and influence on trio playing and his early live performance on the Moog and Arp audio synthesizers. Bley was a long-time resident of the United States. His music has been described by Ben Ratliff of the New York Times as "deeply original and aesthetically aggressive." Bley's prolific output includes influential recordings from the 1950s through to his solo piano records of the 2000s.