John Cage was one of the first early experimentalists I discovered. As a teenager I had already made my way through punk & industrial and had discovered Japanese noise and 60's black free-jazz. Coming across folks like Cage, Xenakis, Stockhausen and Harry Partch pushed me into brand new ways of appreciating music and sound.
Cage's chance operations strategy appealed to my improv side, accompanying my "zen side". His prepared piano stuff appealed to the noise freak in me and his overall unique way of approaching the world was inspirational to me and my friends. The icing on the cake came when I saw the 1966 documentary Sound??, which featured his wacky personality alongside the amazing Rahsaan Roland Kirk (who was already a favorite of mine). His silent piece "4:33" seemed like an exquisite juicy prank on musical snobbery.
While I got a lot out of his work, I do tend to think his analysis of black jazz being "too emotional" shows that he completely missed (or dismissed) the point of it. But his mushroom-hopping nuttiness displayed a man whose mere speech served as some kind of elastic poetry. Add in a few mesostics and some piano-wire banging and you've got a true American original.