Alice Cooper, Slayer, Slipknot and Rob Zombie are among the heavy hitters starring in a new documentary which traces the roots of metal music. Black Sabbath's Tony Iommi, Motorhead's Lemmy and Motley Crue's Vince Neil will also appear in the new film, METAL: A HEAD BANGER'S JOURNEY. As well as targetting the genre's great names, the film also chronicles the history of heavy metal, investigating the sexuality, religion and violence related to the music.