Historically, heavy-metal bands such as Slayer and Metallica have sold images of hellfire and damnation, torment and oblivion, amplified and exaggerated to mythic proportions for a mostly suburban, adolescent base. Even under Saddam Hussein’s violent regime, metal colonized the subconscious of a generation of young Iraqis, who suffered criticism for their scruffy goatees and threw their devil horns — the raised fist with index and pinky fingers extended — like the furtive signal of a secret society.

It wasn’t easy to rock. But once American armed forces began dropping bombs on Baghdad in 2003, followed by an occupation now in its sixth year, things really went to hell. All the apocalyptic language and gruesome cover art that gives metal its demonic kick paled amid the harsh reality experienced daily by the young men who wanted nothing more than to emulate the Western rock bands they idolize. How are you going to crank the volume when the power goes out all the time and there’s a 7 p.m. curfew? What do you do when a Scud missile blows up your equipment van and a bomb wipes out the guitar store?

These are a few of the many cultural questions that underpin “Heavy Metal in Baghdad,” which opens the 15th and final edition of the New York Underground Film Festival tomorrow night at the Anthology Film Archives. It’s an ideal choice for the festival, which is shutting down in part because the gonzo auteurs it has served so well have taken over the Internet. The film was produced by Vice, the Williamsburg-based media empire that promotes latter-day hipster culture and has expanded online with VBS.tv. There, Web surfers can watch bits of “Heavy Metal” along with documentaries of soft-porn photo sessions and “webisodes” of “Toxic Garbage Island.”

Shot by Vice honchos Eddy Moretti and Suroosh Alvi on handheld video cameras with a “we must be nuts to come here” first-person approach, “Heavy Metal in Baghdad” quickly transcends its potential flake factor as it chronicles the struggle of Acrassicauda, a quartet that is purported to be the only heavy metal band in Iraq. The group’s name is Latin for “black scorpion,” an insect common to Iraq, and a usefully descriptive symbol for the band’s impressively stinging attack.

The cameras follow the band over the course of three years, beginning in 2003 when it was first featured in Vice, then picking up again in 2005 when Acrassicauda successfully staged a concert in a downtown Baghdad hotel — though they had to pack up the gear and get lost before nightfall, and the coalition forces guarding the bombed-out site got spooked by all the shaggy Iraqi dudes in their bootleg Iron Maiden T-shirts.

Much of the story is told by the group’s bassist, Firas Al-Lateef, an amiable and talkative young man whose command of English idioms is admirable, if almost comically profane. Though the musicians say they taught themselves from movies and recordings, their accents make them sound a lot like the good ol’ boy American servicemen around whom they’ve spent much of their time. “Dude” is frequently used as verbal punctuation. Weird cultural transliterations abound, such as when Mr. Al-Lateef complains about the difficulty of “head-banging” in an Islamic nation. It seems the up-and-down motion known to metal fans too closely resembles the Jewish act of davening, and could be punished with extreme measures.

It’s tough to keep a band together when it’s too scary to make a 15-minute walk to your guitar player’s house, so the musicians leave home only as a last resort. Gradually, the band drifts into exile before regrouping in Damascus, where the Vice guys arrive to film its first concert in ages. Remarkably, given that there is no metal scene in Damascus, a crowd turns up for the show in a basement café. Acrassicauda is a hit, but the euphoria is dampened by the reality of life in exile. The musicians persist, despite menial jobs that pay almost nothing, knowing that to return home may be fatal. The significance of “Heavy Metal in Baghdad” lies partly in its eagerness to report on the real lives of Iraqis, behind the heavily mediated façade of network news broadcasts, the partisan yammering of self-appointed pundits, and the apathy of the American public. But it’s also a great parable about rock ‘n’ roll as an act of brotherhood and faith in collective survival. Since the film was finished, the band has relocated to Turkey, where it remains in limbo — unable to get visas that would allow the musicians to attend film-festival screenings in Toronto and Berlin. “Electric guitar is a crime against the state,” David Byrne once sang. This movie proves he wasn’t kidding.

“Heavy Metal in Baghdad” screens 8 p.m. Wednesday at the New York Underground Film Festival. Tickets can be purchased at www.brownpapertickets.com/producer/3814.