William Paul Mitchell (born March 21, 1972), better known by the stage name of Large Professor (also Extra P. and Large Pro), is an American rapper and record producer. Based in New York City, he is known as a founding member of the underground hip hop group Main Source and as mentor and frequent collaborator of Nas. About.com ranked Large Professor at No. 13 on its Top 25 Hip-Hop Producers list. Early life and education William Paul Mitchell was born in Harlem, New York City, and raised in Flushing, Queens, New York City, where he attended John Bowne High School. Career Large Professor started making his earliest beats with two turntables, a Casio SK-1 sampler, and pause-tape cassettes before his mentor Paul C taught him how to use an E-mu SP-1200. During his pause tape phase he noted that some of his techniques were different than those of other producers. "I was trying to catch it from a different part of the record. I would catch it from the hi-hat when dudes were just catching it from the one kick. I would catch it from the third hi-hat and be flipping it." In 1989 he joined the group Main Source, which also included Toronto natives K-Cut and Sir Scratch. In 1990 Large produced three tracks for Eric B. & Rakim's Let the Rhythm Hit 'Em, including "In the Ghetto". To make "In the Ghetto", he sampled directly off of a cassette tape of sample ideas Paul C had made for Rakim. Main Source recorded one album with Large called Breaking Atoms, which was released in 1991. It included hits such as "Just Hangin' Out", "Looking at the Front Door", and featured Nas' first public appearance on a track called "Live at the Barbeque", along with Akinyele and Joe Fatal. Large Professor now considers "Looking at the Front Door" one of the most emotional records of his career, later saying "That's a deep record. At that time in life, I was eighteen years old. It was a kid with a pure heart, just writing, and putting his soul out there for the world." In 1992, their success allowed them to record "Fakin' the Funk", a track on the White Men Can't Jump motion-picture soundtrack. Because of business differences, Large and Main Source quietly parted ways and Large went on to sign with Geffen Records. During and after his tenure with Main