It was announced today that Karlheinz Stockhausen died on December 5th at the age of 79. Between 1950 and 2007 he composed over 100 smaller works and several large-scale works, including the longest opera cycle on record. He continued to compose, give concerts, release records and teach composition courses until the very end. He was the epitome of a lifer. His influence was not limited to 20th century classical, but spread through pop and jazz.
Pitchfork posted a more informative article: http://www.pitchforkmedia.com/page/news/47527-karlheinz-stockhausen-rip
You can find out more about the man from www.stockhausen.org