The video for this Run-DMC/Aerosmith collaboration collapsed the distance between rock and rap with a brutally simple image: Aerosmith's Steven Tyler bashing through a wall with a mic stand. ''I think I ripped every muscle in my back,'' he says. The video became a defining moment for both acts. '''Walk This Way' really brought three generations together,'' says Darryl ''DMC'' McDaniels. ''It brought the '70s rockers, the '80s hip-hop fans, and later the '90s rap-rock generation. It was the connecting piece.''