Heavy metal lost one of its icons Sunday when singer Ronnie James Dio died at 67. He was being treated in a Houston hospital for stomach cancer.

    “My heart is broken, Ronnie passed away at 7:45 a.m,” said a statement by his wife, Wendy, posted Sunday on the singer’s Web site and confirmed by publicist Maureen O'Connor.

    Billy Corgan of the Smashing Pumpkins commented on Twitter, "Ronnie was a true gentleman, and obviously one of the best rock singers there will ever be. What a sad loss. ... I only got to meet him once and I can honestly say he was the nicest person I have ever met in music."

    Dio’s neo-operatic voice was one of metal’s most distinctive instruments, an over-the-top stylist perfectly suited for a genre that demanded excess.

    He fronted some of metal’s most revered bands, including a Deep Purple offshoot called Rainbow, the second incarnation of Black Sabbath and his namesake group, Dio. As a result, he had a hand in a half-dozen of metal’s greatest albums, including Sabbath’s “Heaven and Hell” and Dio’s “Holy Diver.” Most recently he was heard fronting a Sabbath offshoot, Heaven and Hell, which released a fine 2009 album, “The Devil You Know,” and toured extensively in 2008-09.

    Dio’s piercing voice and equally flamboyant persona – he is sometimes credited with popularizing the two-fingered “devil’s horns” gesture – made him fodder for affectionate parody, most notably by the best-selling comedy duo Tenacious D.
   
    Dio was born Ronald James Padavona in 1942 in Portsmouth, N.H. He began playing in rock bands starting in the late ‘50s in Cortland, N.Y., and eventually formed the band Elf in 1969. A tour as opening act with Deep Purple led to Dio’s first big break – he caught the ear of guitarist Ritchie Blackmore, who formed the band Rainbow with the vocalist.

    The singer then joined Black Sabbath in 1979 after the departure of Ozzy Osbourne, and sparked one of the group’s best albums, “Heaven and Hell.” He would continue working off and on with Sabbath and Sabbath band members throughout the remainder of his career, in between stints with Dio – a classic, old-school metal band that toured and recorded consistently over the last three decades. The Dio band released 10 studio albums since 1983 and went through numerous lineup changes, with the singer the sole constant.

    For many fans, Dio embodied metal’s virtues, notably its confrontational power and hell-raising subject matter. That affection spilled over into the comedy of Tenacious D – a duo led by movie star Jack Black --- who wrote the tribute song “Dio” and even had the singer appear as an oracle of sorts in the movie “Tenacious D in the Pick of Destiny.” Dio guides the young Black to pursue his dreams. “Now go, my son,” he bellowed, “and rock!”

    greg@gregkot.com