A rap album? The idea was esoteric back in 1984, but the debut full-length by Joseph "Run" Simmons, Darryl "D.M.C." McDaniels, and D.J. Jason "Jam Master J" Mizell changed that—and transformed American pop culture. Songs like "Sucker M.C.s" and "Hard Times" jettisoned the party-hearty disco bounce of early rap for blunt, blasting beats and rhymes. It was music that had the swagger, the attitude—the volume—of rock and roll; on "Rock Box," Run-D.M.C. even had the audacity to toss in a wailing heavy metal guitar. "Our DJ's better than all these bands," they rapped, a boast that turned out to be a prophecy.