Despite its vigorous takedown of music-industry politics and an artist’s journey that presages comedy biopics like 'Walk Hard' by decades, 'CB4' managed to attract some heavyweight talent for its soundtrack, starting with Boogie Down Productions. Their track 'Black Cop' went on to become one of their most famous songs, and has been used in other movies since then. But MC Ren’s “Mayday On The Front Line” is terrific N.W.A.-esque gangsta rap, klonking along on a beat that would have been at home on 'Straight Outta Compton,' while Fu-Schnickens’ 'Sneaking Up On Ya' offers a different kind of vintage feel – namely, the sense that gimmicky styles will always be short-lived, even if they’re totally great while they’re in vogue. But the trifecta of 'Rapper’s Delight,' 'Straight Outta Locash' and 'Sweat From My Balls' encapsulates everything that’s both great and terrible about rap, combining familiar hooks with gobsmacking lyrics to create a time capsule of where rap music had been, and where it was going.