Black Sabbath - The Ballet: Heavy metal meets classical dance in new Birmingham Royal Ballet show

Black Sabbath guitarist Tony Iommi says he expects audiences will be "shouting and singing" when Carlos Acosta's Birmingham Royal Ballet takes to the stage in a work based on the band's back catalogue.

Speaking at a special rehearsal session which Sky News was invited along to film, he said: "I love Carlos' approach, he'll go out there and do something he believes in… and it's the same approach Sabbath has had."

"People don't step out the box enough," he added.

"In the early days it was very difficult to do what we were doing, coming out at the same time as music like soul, but you keep on believing in it."

Dances for the sold-out show, which begins in September, are still being choreographed but more is known of the music - the three-act ballet will feature eight re-orchestrated songs by the Birmingham rockers.

Classic tracks in the show include Paranoid, Iron Man, War Pigs and Sabbath Bloody Sabbath.

New compositions inspired by the band will also be played live by the orchestra with guitars and drums to be integrated into the performance.

Black Sabbath formed in 1969 with lead singer Ozzy Osbourne, guitarist Iommi, bassist Geezer Butler and drummer Bill Ward.

Birmingham Royal Ballet's Artistic director, Cuban ballet star Carlos Acosta, says he wishes he was in the cast of the new ballet himself.

He says: "I don't think there has ever been something like this.

"I am very jealous that I'm not in the cast - I'm the director so maybe I can change that - but it's very contagious."

According to Acosta, around 68% of tickets have been sold to metal fans who aren't exactly known for being well-behaved.

The band's frontman Osbourne himself infamously bit the head off of a bat and snorted a line of ants.

Sabbath fans' reputation for letting loose is something Iommi has already forewarned about, saying: "I did say to Carlos they're liable to start getting up singing the words because that's what they do and he said, 'that's great man,' so we'll see!"

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Black Sabbath - The Ballet runs at the Birmingham Hippodrome from 23 September to 30 September, and in London's Sadler's Wells between the 18 and 21 October - tickets for which go on sale on 22 May.