The metal giants will release new album 13 � their first with Ozzy Osbourne since 1978 �on June 10, and tour the UK in December. Butler tells The Metal Forge: "Since all our albums date back to the 1970s, that is the decade we will be dealing with. We always have to play the staples, such as Iron Man, Paranoid, Black Sabbath, War Pigs, Children Of The Grave, but it's good to include more obscure stuff."

Thinking back to their first studio experiences, he recalls: "The first and second albums were recorded on two four-track machines, the first album in two days, the second in five days. It was basically like doing a live gig in the studio.