John Milton Cage Jr. was an American composer, music theorist, artist, and philosopher. A pioneer of indeterminacy in music, electroacoustic music, and non-standard use of musical instruments, Cage was one of the leading figures of the post-war avant-garde. Critics have lauded him as one of the most influential composers of the 20th century. He was also instrumental in the development of modern dance, mostly through his association with choreographer Merce Cunningham, who was also Cage's romantic partner for most of their lives.
The above text from the Wikipedia article "John Cage" text is available under CC BY-SA 3.0.