If Grandmaster Flash had only released his most famous single, he would still be one of the most significant figures in hip-hop history. “The Adventures of Grandmaster Flash on the Wheels of Steel,” pressed by Sugar Hill Records in 1981, is a seven-minute live DJ mix so full of technical virtuosity and inspired synthesis that its rearrangement of early hip-hop and its antecedents in other genres can distract from the fact that it’s the first prominent recording of record scratching. Of course, Flash’s brilliance cannot be contained on one white label. The Bronx native corralled Melle Mel, The Kid Creole, and Cowboy—who coined the term hip-hop—under the name Grandmaster Flash and the Furious Five. Together, they helped codify the genre with 1979’s “Superrappin’” and cut its first truly great piece of sociopolitical commentary with the Melle Mel-led “The Message” in 1982. With the core technical tenets of live and recorded hip-hop and the furthest expanses of its potential for reportage and documentary, nearly all roads lead back to Flash.