The veteran Queens rapper-producer is widely recognized as an uncredited producer on Eric B & Rakim's third album, 1990's Let the Rhythm Hit 'Em. "I wasn’t on the professional side, like, ‘Show me the contracts,'" Pro told Complex years later. "I was just in there doing beats. I had no contractual obligations with Eric B., because that’s who had me in there... It wasn’t like, ‘You’re going to get credited for this and that.’"
(Photos from left: Ray Tamarra/Getty Images, Courtesy of RakimandEricB.com)