As Guru said himself on one of Gang Starr’s innumerable classic songs, “It’s mostly the voice.” The rapper, born Keith Elam in 1961, was blessed with one of the most inimitable intonations to ever grace a microphone. On 1994’s “Mass Appeal”, he described it as a monotone, but even that was a point of pride: it meant he didn’t lean on gimmicks. Though he and his partner in Gang Starr, DJ Premier, were not born in the city—Guru grew up in Boston, Preemo around Houston—together they helped define ’90s New York hip-hop. The four albums they released in that decade, from 1991’s Step in the Arena to ’98’s Moment of Truth, are considered classics by true-school rap fans, with Preemo’s robust sample chops serving as the ideal canvas for Guru’s wickedly disciplined style. On his own, Guru embraced another avenue of rap production: his Jazzmatazz series is one of the key points of convergence between the two genres. When he passed away in 2010, he was widely celebrated as one of the most accomplished MCs in hip-hop history.