Rock the Bells was an annual hip-hop festival that originally took place in Southern California only, but has since toured throughout the world. The concert featured a line-up of high-profile alternative hip-hop artists, often headlined by a more mainstream artist. The first festival was held in 2004, featuring a re-united Wu-Tang Clan, who performed four months before Ol' Dirty Bastard's death. That festival is covered in depth by a documentary film also called Rock the Bells.