One of the most important composers of the 20th Century, German avant-garde and electronic composer Karlheinz Stockhausen, has died. The cause of his Wednesday death, which was announced today, is unknown at this point.

Stockhausen made his way into pop culture when his image appeared on the Beatles album cover to the "Sgt. Pepper's Lonely Hearts Club Band" album. After 9/11, his name surfaced in the main stream media when the press misinterpreted a statement of his about the attack in New York being a great "work of art."

One of LAist's favorite Stockhausen compositions is the Helicopter Quartet, which calls for a string quarter and four helicopters with pilots.

Photo by edvvc via Flickr