In the early-to-mid-1980s, the line was firmly drawn between rock and hip-hop. But the wall came tumbling down once producer Rick Rubin persuaded Run-DMC to give Aerosmith's "Walk This Way" a rap makeover. "Run-DMC liked the beat, but they didn't want to sing those words," Rubin told Rolling Stone. "I explained that would defeat the purpose. There were still people who didn't think rap was music. The goal was, here's a song you've heard. And our version isn't so different that theirs is music and ours isn't."