Although he's one of the most influential figures in twentieth century music, Philip Glass has nevertheless earned the ire of some of his fellow Avant-Gardists for both his enormous success and his coinage of minimalist theory. A Julliard-trained classical musician whose ideas were greatly transformed when he was hired to transcribe Ravi Shankar's work, Glass embraced rhythm and repetition over the standard classical rules -- rules which had previously applied even to Avant-Garde classical. He was met with massive success during the '70s and '80s, working in concert halls, theatre, opera, film and even on pop recordings. Though often accused of overt repetition, it must be noted that Glass' music has become increasingly rich over the years, while still managing to maintain a certain accessibility on a basic, emotional level. His advances have trickled down into both the popular music we hear (David Bowie, Aphex Twin) and the alternate musical avenues that post-Glass artists are free to explore.