Black Sabbath: Inside: 1970-1992 (2004)

This is the long awaited critical review of the music of Black Sabbath on record, on film and on stage.
Using rare previously unreleased film of the original Ozzy Osbourne line-up from 1971 never before available on Dvd, this superb independent film sets out to discover what makes a great band and poses the tricky question: who was the best Sabbath singer Ozzy, Dio or Martin?