Rock Box

Larry Smith and Russell Simmons produced Rock Box, which Profile released in 1984. The group had to wait for the metal band Riot to finish their studio time, and Run said that after seeing the guitars they wanted some too. DMC said the idea of rock guitar came from Smith. DMC had first wanted to rhyme over Billy Squier's The Big Beat, but Smith had him lay out a beat on the DMX drum machine instead. Smith played bass and called in his friend Eddie Martinez from Hollis, who recorded one riff and then stacked a harmony and a solo on top. DMC recalled coming back to find bells, guitar and a bassline on the track. Run and DMC were not happy at first with the guitar, and the group gave Kool DJ Red Alert a version without it, but the guitar version proved the more popular.

Steve Kahn directed the video, shot at the club Danceteria. It was the first hip-hop video in regular rotation on MTV. Run said later that Rock Box, rather than King of Rock or Walk This Way, was "the record that took us out of the hood." Roy Trakin of Creem called it "a searing rap rocker." Tom Breihan of Pitchfork was less taken, calling it the debut's only real misstep. It had sold more than 750,000 copies by May 1985.