WORLD TOUR?
Bonizzi, who names bands such as rockers Megadeth and Dream Theater as favourites, also sings about God and faith but says he has no intention of converting listeners to Christianity.
"I never did it to preach, I did it because music is beautiful ... If I want to convert people, I simply want to convert them to life, to welcome life, to enjoy life," he said.
"I am religious and I am a priest but I am not doing this to convert people to Christ, to faith or the Church, but for them to try to understand life, to be able to enjoy it. Nothing more."
One of 10 children, Bonizzi grew up near the northern Italian town of Cremona. He worked as a hairdresser, welder and in a factory before a brief military stint and then joined the Capuchin order at age 29.
The friar, who performs about 100-150 concerts a year, says heavy metal fans have warmly welcomed him and he distances the music genre from satanism.
"About 90 percent are very good, they accept (me), the other 10 percent are more extreme," he said.
"They say 'We don't want people from the Church.' There are those who profess to be satanists but there are only two or three groups that explicitly claim to be so. I do not really know whether they really are, they claim to be."
Bonizzi sings in Italian and Latin, but "Misteri", his 18th CD, is being translated into English. So far, he only performs in Italy, but he says he has received invitations to put on shows in Japan and Brazil: "I would like to do a world tour."
Unsurprisingly, his singing has attracted much attention. At the "Gods of Metal" festival, fans were screaming his name even before he began performing.
"We do not understand what has happened. It's not as if we had done any publicity, the CD wasn't even out yet. I've sung three times at 'Gods of Metal' already," he said. "I've been doing this for 10 years, and it's only really now that it has taken off."
The friar, who was even given a "heavy metal rosary" by a non-believer fan, performs with three other guitarists and a drummer, who are much younger than him.
"At first I was a bit sceptical about this project because I thought it was weird to have a mix of heavy metal and a Capuchin friar," said 38 year-old guitarist Cesare Zanotti.
"But after two minutes with him, you forget he is a friar -- his age -- you forget everything and he becomes a member of the group. He gave me more energy than bandmates who are my age or younger are able to. When you play with him, there are smiles and a lot of energy which is fundamental for heavy metal."
The Vatican has not voiced an opinion on Bonizzi's singing but he says his superiors have not said anything negative to him about it. He says his fellow Capuchin friars accept what he does, although he does not play for them: "I could sing this (heavy metal), but they would say it's too loud."
