He’s a renowned riff merchant, whose driving power chords were the force behind classic 1970s hard rock tunes such asandNow, influential Black Sabbath guitaristhas shocked many heavy metal fans by penning this year’sfor Armenia.Taking part in Europe’s," which is more famous forandthan it is for its music, is certainly an unexpected move for the man the rock 'n' roll magazine “Rolling Stone” once ranked as theof all time. (He himself has described his Eurovision entry as a “new experience.”)Iommi’s involvement in the contest actually stems from his charity work in Armenia.He waswho helped raise funds after anear the city of Gyumri in 1988, which left tens of thousands of people homeless and killed at least 25,000.The guitarist subsequently visited Armenia in 2009 when he was given the country’s order of honor and he also became involved in rebuilding a music school there.This gave Armenia’s Eurovision representatives an opportunity to ask him if he would be interested in writing a song for them."I first said, 'Oh God, I don't know' -- it seemed really strange, me doing a Eurovision song, I don't usually do that," heearlier this month. "But I said, 'I've got a rock ballad, I'll send it over.'"After that, it seems one thing led to another and Iommi’s “Lonely Planet” is now set to be performed by Armenian band Dorians in the Eurovision semifinals on 16 May in Sweden.Although it’s a far cry from the likes ofIommi says he’s “really pleased how it’s turned out” despite the fact that he expects it to be “slagged [off].”It’s been a busy time of late for the legendary guitarist, who recently underwent treatment for cancer.Besides taking time out to write Eurovision entries, Iommi has been working in the studio with original Black Sabbath members Ozzy Osbourne and Geezer Butler.The band is scheduled to release its first new album in 33 years later this year.-- Coilin O'Connor