If you saw Black Sabbath's first ever gig, you wouldn't have recognised greatness.
Back in 1968, they had the decidedly less sinister name of The Polka Tulk Blues Band, and came complete with a saxophonist and bottleneck guitar player.
A year later, they'd slimmed down, found a new name and invented heavy metal. Few bands are so inextricably linked with a musical genre, but Sabbath set the template for everyone from Motörhead and AC/DC to Metallica and Guns 'n' Roses.
Along the way, singer Ozzy Osbourne, who has died at the age of 76, became one of rock's most influential figures, with an electrifying and unpredictable stage presence and an almost mythological intake of drugs.
"If anyone has lived the debauched rock 'n' roll lifestyle," he once admitted, "I suppose it's me."
