This documentary of the metal band's history covers its blues origins in England through frontman Ozzy Osbourne quitting to begin his solo career. Group members Geezer Butler and Tony Iommi provide commentary throughout the piece, which contains clips from a variety performances -- including footage of the group when they were known as Earth and playing electric blues. The band that proved to sprout the heavy metal movement, Black Sabbath's effects on music are documented in this film, showing how their influences manifested their unique and groundbreaking sound through years of collaboration. ~ Sarah Sloboda, All Movie Guide