With a pioneering sound that essentially created the genre of heavy metal, it’s no overstatement to call Black Sabbath one of the most important rock bands of all time. In 1967, bassist and lyricist Geezer Butler formed Rare Breed,

They created some incredible songs during their run but there's one Black Sabbath song that Ozzy Osbourne considers to be their most important

Why are Black Sabbath coming back? Who else is on the bill? How do I get tickets? We answer all your questions about this summer’s Back To The Beginning extravaganza