Rap Collaborations with Pop Singers

Rappers and singers have been collaborating since Melle Mel rocked it with Chaka Khan in 1984. In the new millennium, these partnerships have gotten even bigger, with vocalists sending their falsettos heavenward, while MCs get gritty down below. This pairing reaches its peak on JAY Z's loud-quiet-loud Timberlake duet "Holy Grail" and supercharges a playlist that risks blowing out your speakers.