The original line-up of Black Sabbath - singer Ozzy Osbourne, guitarist Tony Iommi, bassist Geezer Butler and drummer Bill Ward - has officially reformed. Or have they?

Either way, metal owes Black Sabbath a huge debt. They were true pioneers that emerged from the poverty of Aston, Birmingham in the 1960s to bring a brand of blues so heavy a whole new name would have to be invented for it.

Some claim to have got there first but when that doom-sodden riff kicked off the unholy trinity of song, album and band Black Sabbath, the world knew that the spirit of heavy metal had truly arrived.

It was the beginning of an incredible career that's still playing out, but there's a great deal more to Sabbath's rollercoaster story than Ozzy, Iron Man and Paranoid...