William Paul Mitchell (born March 21, 1972 in Harlem, New York), best known as Large Professor, also as Large Pro and Xtra P, is a New York based hip hop record producer and rapper. He is best known as a member of the influential underground hip hop group Main Source, and for discovering popular rapper Nas.http://www.matadorrecords.com/large_professor/biography.html Biography Early career His production career started early in his adolescence. As a young teenager, he would make 'pause tapes' which he would pause a beat and blend it in with other sequences. Eventually, he mananged to own a Casio SK-1 sampling keyboard which allowed him to make his beats at the comfort of his own home. He became a protege of the late Paul C, a record producer and musician, with whom he credits for teaching him virtually everything he knows about record production as well as the associated t