Here’s a music history documentary that doesn’t answer its titular question for a long while.

All through the punk and metal clubs of 1970s New York, musicians, club owners, fellow fans and movers and shakers would see this kid — underage, Puerto Rican, flamboyantly gay, in the front row or backstage, a hanger-on from Brooklyn’s Hassidic quarter.

And one and all were moved to ask, “Who the F*** IS that Guy?”

Michael Alago was everywhere, glimpsed in the front row in live performance footage of the Dead Boys at CBGB’s, grabbing fan “selfies” with every musician under the sun before we called those “Look who I’M with” vanity shots by that name.

“Who the F***” captures how this gay Puerto Rican punk and metal fan turned the fact that he stood out from that crowd — and how — into a career in the music industry, signing everybody from Metallica to Rob Zombie to their first big recording contracts, making them famous and reveling in the scene and the reflected glory.

Drew Stone is the credited director, but in every scene, as Alago chooses locations to tell his story, narrates his story and calls in favors to fill the screen with everyone from Cyndi Lauper to every member of Metallica (many of whom took producer credits on the film to get it made), it’s Alago’s movie — we witness music industry self-mythologizing at its most naked.

But it’s a fun vanity project, an interesting history as seen from its insiders — the rivalry between the famous clubs — Max’s Kansas City, CBGB’s — and the nearly forgotten — The Ritx, L’Amour — the bending of punk into metal (speed metal, death metal, etc.).

Agalo glamorizes the sordid pre-AIDS Golden Age of Gay Cruising in the New York, owns up to falling into the booze and drugs that tempt anyone who dives into the music industry– somehow, every story has him “getting the boy” or winning the fight or surviving — and takes credit for exposing many a metal fan or metal band to the first openly gay man many of them had ever met.

He tells his story to the camera, or sometimes is captured on stage reading from a sort of one-man confessional about the era. His connections to the great one-man-show artist Eric Bogosian (“Talk Radio”) or inexplicably prolific hack filmmaker Dito Montiel are never really explained, but here they are — friends bearing witness.

John Lydon, formerly Johnny Rotten, remembers Michael booking his band Public Image Ltd. into The Ritz, where the former Sex Pistol started a riot by having them perform behind a hide-from-the-audience screen.

“‘Hey, the DRINKS are on me,'” Lydon laughs, remembering the night. “THAT’s how you stop a riot!”

The take away? Agalo had an ear for metal talent and a nose for charisma, but more importantly, an eye for the brawny, tattooed males who would take over that scene in the ’80s.

And in that world of piercings, weightlifting, skinheads and homophobia, he made his mark and forced those inhabiting that space “to put up with me.”

Good on him.

MPAA Rating: unrated, with profanity, drug discussions, promiscuity

Cast: Michael Alago, James Hetfield, Cyndi Lauper, Rob Zombie

Credits:Directed by Drew Stone. An XLRator Media release.

Running time: 1:17