Playing in a rock band - it's a clich� dream perhaps and one most teenagers hold dear. That Holy Grail of a high school quest brought 14-year-old friends Steve (Lips) Kudlow and Robb Reiner together in 1973 to launch the Canadian heavy metal band Anvil.

In a musical generation that included Metallica, Slayer and Anthrax, these metal-thrashing Toronto musicians never hit the big time. In fact, Anvil's 50-something band members are still on the road playing small bars and modest-sized halls just for the love of it. But long acknowledged by peers and fans as the "Fathers of Power Metal," Anvil will finally enjoy some star billing at the 2008 Hot Docs Canadian International Documentary Festival in Toronto.

"Anvil! The Story of Anvil" -- an uplifting film by director Sacha Gervasi -- kicks off North America's largest documentary festival on April 17.

Underground no more

Curiosity inspired "The Terminal" screenwriter Gervasi, a former Anvil roadie, to track down these heroes of Canadian metal and discover what they were up to.

"Sacha hadn't seen us for many years," says Kudlow, 52, Anvil's lead guitarist and vocalist. "He thought it was amazing that a couple of guys who had put together a band at 14 had lasted this long."

Known for such influential albums as "Metal on Metal" (1982), "Worth the Weight" (1991) and "Speed of Sound" (1998), Anvil's impact on the biggest heavy metal bands was undeniable, says Gervasi.

"I felt it was important for the truth about Anvil to be acknowledged," says Gervasi. Born in London, England in 1966, Gervasi first saw Anvil play in a local club in 1982. "Anyone who knows the music from those times knows how important Anvil was to the heavy metal movement. Just listen to a song like '666' on 'Metal on Metal.' It's widely considered to be one of the first speed metal songs. That's a year or two before Anthrax, Megadeath or Slayer."

As Gervasi says, "That speed, rhythm, intensity and power you hear in Metallica and other bands like them comes from Anvil. Performers in these big bands knew this was true, even if audiences didn't."

A passion to play

The end result is a topsy-turvy documentary by Gervasi that follows Anvil's members as they conclude a calamitous European tour and start recording their 13th album.

"These guys have struggled in real obscurity for close to 30 years," says Gervasi. "No one does it for the love anymore in this business. I think that is an important message that's been dressed up in this comedic package."

But staying underground for 30 years had its purpose, says Kudlow.

"We're not Bon Jovi. Not by any stretch. But we've been as successful as we wanted to be," says Kudlow. "We never tailored our music to get a record deal. We never sold out. We're proud of that. How many bands can say that today?"

Anvil's stick-to-it passion also transcends this Hot Doc's musical genre. "This is more than a heavy metal movie," says Kudlow. "It's packed with emotion. There's sadness, giddiness, depression...all kinds of feelings that people with big dreams can relate to."

The documentary's brutal honesty about life on the road is also universally compelling. "The film shows the real thing -- the headaches, insanity and real joys most musicians know," says Kudlow.

Happy just to break even after any Anvil performance, Kudlow says, "Big rock stars make up such a small minority in this business. Ninety per cent of musicians never tour. They never make a record or make big money. But they still make music. They do it because it's their passion."

Age of enlightenment

With no plans to give up rocking, Anvil's perseverance in the tough, fickle music biz is the real star of Gervasi's film.

"Lots of people have dreams that they let go as they get older. But that's why I think people will love this movie," says Kudlow. "Even in the face of disaster it's a positive look at humanity. It's about the spirit of life and going for your dreams at any cost."

As Kudlow says, "We never realized superstardom. But we never lost sight of our dream. That's what keeps us going."

Should the likes of Bon Jovi or Justin Timberlake ever take in a screening of "Anvil!" Kudlow says, "They should want to hug me. Even Tom Araya, the bass player with Slayer, has told me how blown away he was that we persevered through all these years. He'd never have done it," Kudlow laughs. "But he wonders how the hell we did?"