(born Colfax, California, 1935) American composer and performer who experimented with echo effects and the technology of tape recording that developed in the 1960s. His musical score In C (1964) was one of the first works to bring compositional minimalism to a mainstream audience. Influenced by modal jazz and Indian classical music, Riley is known for his extensive keyboard improvisations. He studied with musician Pandit Pran Nath from 1970 until the Indian master's death in 1996.