As I write this, I’m blasting Green Day’s 2004 “American Idiot” CD only because the cast album of their theatrical adaptation hasn’t yet been recorded.

In both incarnations, the music is at once hummable and subversive, driving and spellbinding.

I’m thrilled from the very start of Michael Mayer’s collaboration with Green Day frontman Billie Joe Armstrong, Friday night at Berkeley Repertory Theatre. The opening notes of the show’s eponymous song – accompanied by aggressive headbanging from leading man John Gallagher Jr. as Johnny, aka “Jesus of Suburbia” – rip through the 600-seat Roda Theatre, and everyone sits up a little straighter.

Much, but not all, of this audience – nine weeks into the run, as the show enters the final days of its final extension in Berkeley – have come because they’re either fans of the band or have heard the buzz about how great this show is (the San Jose Mercury News calls it “the hottest show of a searing fall theater season”). There are teenagers in fingerless gloves sitting next to early-60’s couples who are there as part of their subscriber packages, but the latter are the minority; this is a young crowd. So when those first notes blast out across the theatre, we know what we’re in for.

The music is loud. Berkeley Rep offers earplugs in the lobby – a concession, I suppose, to subscribers who might be used to a more traditional brand of theatre – but I eschew them. There is no question that this music – on stage or through headphones – is meant to be heard at maximum decibels.

Because I know the “American Idiot” album so well (in addition to Green Day’s newer “21st Century Breakdown,” from which an additional four songs are culled for the show), I expect it to take some getting used to to hear voices other than Billie Joe’s on these particular melodies and lyrics. But Gallagher has a similar grittiness to his voice, and his delivery is so perfectly rebellious, that it proves easy to put Billie Joe’s image on the back burner, and buy into these as our protagonist’s original and mutinous thoughts.

American Idiot is a sung-through musical – very little dialogue is used outside the songs. At first, I don’t love the effect; it makes the few spoken lines seem somewhat awkward, as if they have been added only to fill in gaps in the exposition of the music. In addition, I worry that patrons who are not already familiar with Green Day might miss a lot of the context; the lyrics come fast and furious, and without previous knowledge of the words, I can imagine that a lot could go over an audience member’s head.

But then I have a little revelation about this show.

American Idiot is not like other musicals. In fact, the more I think about it, the more it doesn’t really strike me as “musical theatre” at all.

I’m going to venture to say that American Idiot is a brand new form of theatre: the long-form, live-staged Rock Music Video.

Not a jukebox musical; not even an adaptation (any more than Lady Gaga’s new video is an adaptation of her hit single “Bad Romance”). This is the artists’ own fleshing out of their vision – but instead of being done on-screen, it’s brought to us live in-person: loud and unapologetic, completely impossible to tune out or otherwise ignore (even if you don’t catch every word.)

I’m watching Gallagher and his castmates, but I am also taking in a remarkable set, soaring up stories into the theatre’s fly system. A huge, flat back wall is papered with newspaper headlines, advertisements and propaganda all in black and white; nearly 30 televisions are scattered at random on all levels, showing animation, commercials, old TV-show clips, Bush-era news items, and violent explosions. The band (not Green Day themselves, kids) is onstage amongst the actors, with musicians on several levels of a fire-escape-ish scaffolding reminiscent of Collins’ Christmas tree in Rent. Half a car, one actor, and later a shopping cart, hang from the rafters. There is so much to look at that I’m at once overwhelmed and mesmerized, which I suspect is exactly the intention of the designers.

From the breathtaking set and lighting design, to an exhaustingly full-body commitment from Gallagher, to a strong supporting cast (it’s a pleasure to see Spring Awakening alums Gerard Canonico and a hardly recognizable Brian Charles Johnson in the ensemble, plus the bewitching Rebecca Naomi Jones from Passing Strange as the leading lady “Whatshername”), there is little I’d have changed. I was rapt from start to finish, wishing from the first number that I’d be in Berkeley long enough to see the show again.

In addition to Gallagher and Jones, I must single out Tony Vincent as St. Jimmy, a striking and unusual actor who brings Jimmy to life as one part Vampire, three parts Hypnotist, and altogether scary/beautiful. Jimmy is Johnny’s bad influence, the devil on his shoulder, who introduces him to heroin; it’s not entirely clear if he actually exists or if he’s a kind of “Brad-Pitt-in-Fight-Club” manifestation of Johnny’s battle with his own dark side. In any case, I find it impossible to tear my eyes away from Vincent, with his half-shaved head and alienesque ultra-long arms; not to mention a voice that peels through the Roda Theatre with a clarity that would enthrall even the most skeptical gray-haired matinee lady.

There is some tweaking to be done before the show comes to Broadway. I’m thinking specifically of a high-wire hospital dance in which Johnny’s buddy Tunny (Matt Caplan), injured at war, hallucinates an “Extraordinary Girl” in Middle Eastern dress (the flying struck me as just a little too “Princess Jasmine on a Magic Carpet”).

But overall, American Idiot is a force – exhilerating, thought-provoking, and powerful. As Passing Strange (also a Berkeley Rep original) brought us Broadway’s first Live Concert/ Storytelling hybrid, American Idiot breaks ground as the first live-action, album-length Music Video to hit the Great White Way.

There’s no date announced yet for the Broadway incarnation of the show, and its New York home has not yet been revealed (although I’m hearing buzz that Jujamcyn Theaters is interested, which means it will likely end up at the St. James, the Walter Kerr, or the Eugene O’Neill). But the show is coming to Broadway, which means you’ll have no excuse to miss it.

Trust me, you’ll want to see American Idiot. And just think – someday, you can tell your kids you were there when Green Day broke theatrical ground.

BroadwayGirlNYC: A fan’s perspective on all things theatre in NYC & beyond. Show reviews, actor sightings, gossip & more. Follow her updates at @BroadwayGirlNYC.