Black Sabbath's Tony Iommi writes choral music for Birmingham Cathedral

Dean Ogle said Tony Iommi's song was a "wonderful gift" for the cathedral

Black Sabbath founder Tony Iommi has swapped his heavy metal roots for an ecclesiastical project by writing and producing a piece of choral music.

The five-minute acoustic arrangement for Birmingham Cathedral was a huge departure for the musician once accused of being a Satanist.

The 68-year-old said the song, How Good It Is, was to give something back to the city he hails from.

He said the track was "just a little bit different to Sabbath".

The project was born out of his friendship with the Dean of Birmingham, the Very Reverend Catherine Ogle, which developed when he was battling cancer in 2012.

The lyrics for the piece were inspired by Psalm 133 which talks about people living together in unity which "is what Birmingham is all about", Dean Ogle said.

Tony Iommi (l), Ozzy Osbourne (centre) and Geezer Butler (r) formed their first band in 1968

"Tony and I were introduced by a mutual friend and we discussed a possible music collaboration sometime in the future," she said.

"Then, when Tony was unwell, we got to know one another better when I began to pray for him and kept in touch with Tony and his wife about his health.

"This is a most wonderful gift Tony offered to the cathedral."

Iommi, whose band's front-man is well-known hell-raiser Ozzy Osbourne, said the group, whose reputation is for being pioneers in heavy metal, have previously done instrumental work with orchestras which was something he enjoyed.

"This is a completely new piece of music and I'm really pleased with it."

As for their famed links with the occult, Iommi admitted in a BBC interview in 2013 that the group had "dabbled" in their younger days, but felt it was really an image invented by their record label when a picture of an upside down cross was used on their first album.

Tony Iommi plays his guitar with the choir

"People used to think we were Satanists but we weren't," he said.

"The songs were the opposite and all about the dangers of Black Magic and Satanism.

"The closest we came was Black Magic chocolates."

The new song was played to the public in the cathedral on Thursday which garnered a "beautiful" reaction, Dean Ogle said.

"We're so pleased with what people have been saying.

"We're particularly touched by Tony's fans who have got in touch to say how much they like it - some are quite surprised but 'beautiful' is a word that keeps coming up.

"Who knows if there will be more collaborations?"