Philip Glass (born January 31, 1937) is an American composer. One of the highest profile composers writing “classical” music today, he is often said to be one of the most influential composers of the late 20th century. His music is also often (controversially) described as minimalist, along with the work of the other “major minimalists” La Monte Young, Terry Riley and Steve Reich.
He has lately distanced himself from the “minimalist” label, describing himself instead as a composer of “music with repetitive structures.” Though his early mature music shares much with what is normally called “minimalist”, he has since evolved stylistically. Currently, he describes himself as a “Classicist”, pointing out that he is trained in harmony and counterpoint and studied such composers as Franz Schubert, Johann Sebastian Bach and Wolfgang Amadeus Mozart with Nadia Boulanger. (Taken from the complete wikipedia entry, which can be found here)