“Long Live Rock,” a doc about the undying devotion of aging white folks to their favorite metal bands, is littered with tattoo stories, accident stories, mosh pit and crowd surfing tales and a few yarns that begin with “We were drunk, so” or “We were so drunk,” oft told from the front porch of a single wide followed by a Sirius dj bitching about how “tired” he is of “stereotypes” about “this audience.”

Irony died three Metallica bassists ago.

But I kid. No, not all of them have gotten that AARP card in the mail, and the fact that they’ll never end up in “yacht rock” fandom says something. Not with all that ink and tinnitus.

Jonathan McHugh’s documentary, “Long Live Rock: Celebrate the Chaos” has a chaotic organization all its own. It purports to be from the fan’s perspective, and catches up with a lot of rural 50somethings, and a few folks outside that demo, who recapture their “7-11 parking lot” youth at the big rock festivals that are how the Slipknots and basically anybody who isn’t Ozzy or Metallica make their money these days.

But there are also scores of mostly ’80s-vintage band musicians, from Metallica, Guns’n Roses, et al, making the case that “we’re playing to entire families — parents, kids and grandkids!”

As an entertainment journalist, the first time I heard a musician claim that was for a still-touring vintage Big Band from the ’40s, on the road into the ’80s.

An oddball psychologist, and the eye-rolling and omnipresent Dr. Drew are here to talk about finding connection, one’s “tribe,” and what that gives devotees.

But they’re also on camera to talk about the rash of suicides and ODs that occurred just before the film went into production — Chris Cornell of Soundgarden, Chester Bennington of Linkin Park, the “demons” many spotlight performers face. Duff McKagan of GNR recalls drinking and drugging until “my pancreas burst.”

Rock’n Roll!

The film’s problem isn’t those excesses or its fans, it’s when it wanders all over the place instead of focusing on the most devoted metal fans. The people who hang onto the music, tattoo lyrics and logos on their arms and torsos, who turn these festivals into tailgating affairs, meeting up for beers and good times with friends, are mostly here for some good, clean and loud fun.

There’s a generous sampling of lives seeking “escape” and the poor judgment that often accompanies that — the potential violence of the mosh pit, the “groping” risks that “brave” woman face when crowd-surfing. The ex-con and the prison guard who run into each other at concerts now is a nice inclusion., the 30ish gun-nut nurse a bit of an eyebrow raiser.

But music is music, and another generation of performers have established themselves — Halestorm, et al — suggesting that pronouncements of “rock is dead” by Gene Simmons, Forbes Magazine et al, in the opening of the movie might be premature.

Music is “cyclical,” as more than one promoter says here, and there’s a chance that after a couple of generations of rap/pop mania, kids will pick up guitars or fall for musicians who do.

Still, you can’t help notice the elephant in the room that McHugh ignores. Despite the inclusion of 63 year-old Ice-T and acts with African American performers on the festival bills, the audience they’re playing to (as shown here at least) is entirely white, almost entirely over 30, mostly 50ish.

And the focus on festivals as “proof” of the future of the genre and the scene is ludicrous. Crowded-bill festivals are to metal what county and state fairs are to country music and cruise ships are to pop stars.

They’re the last stop on the road to oblivion.

MPA Rating: unrated, drinking, profanity

Cast: Lars Ullrich, Lzzy Hale, Ice-T, Duff McKagan, Machine Gun Kelly, Dr. Drew Pinsky, Tom Morello, etc.

Credits: Directed by Jonathan McHugh. An Abramorama release.

Running time: 1:23