Until Run-DMC came along in the early 1980s, most hip-hop music wasn't much more than nursery rhymes over disco loops. They popularized the idea of rap as a new kind of rock & roll--the voice of the streets set to the raw sounds of a turntablist one-man-band. The group even managed to pioneer the collision of rock and rap with a groundbreaking take on Aerosmith's "Walk This Way." Run-DMC is now viewed as the avatar of old-school hip-hop, almost quaint by 21st-century gangsta standards, but undeniably influential. Sadly, Run-DMC disbanded in 2002, after the tragic murder of Jam Master Jay, the group's groundbreaking DJ.