Whoever’s out-there idea it was to revive “Hair,” the 60s-era rock musical that time has preserved like a well-pressed flower, peace and love to you. Theater doesn’t get much better than this.

Deserving a lot of the credit is Diane Paulus, whose direction of this revival has, like a good lather-rinse-and-repeat cycle, given “Hair” new life and a vibrant shine. But she’s working with some pretty irresistible material — Galt MacDermot’s first-of-its-kind rock score, sublimely interpreted by the songwriting team of Gerome Ragni and James Rado. It takes hearing “Aquarius” — probably the best first song of any musical — exactly once to be convinced of these musicians’ talent. 

Dressing up the unstoppably infectious score this time around is Karole Armitage’s flailing, free-spirited choreography and some brilliant full-spectrum light work by Kevin Adams. The result is a rollicking, euphoric trip, as current in 2011 as it no doubt was in 1967 — surprising, given that this is a show about hippies.

And that’s basically everything that can be said about the plot, because there really isn’t one. Like the counterculture it essentializes, “Hair” rejects traditional structures. A concept musical, the show is played revue-style, with members of its central “tribe” taking turns to express their discontent with the system. They mock their elders, smoke pot, trip out, have every kind of sex (clothed, except in one nonsexual climactic scene) and curse when they have nothing better to say.

If there’s a main character, it’s Claude (Paris Remillard), who acts out against his conservative parents by growing his hair out, wearing love beads and sporting tight-fitting clothing. But Claude isn’t the hippie his friends are. While they are burning their Vietnam War draft cards, Claude balks: Is he ready to embrace the counterculture unreservedly, or does he recognize it for what it is — a phase that merely gives transitory expression to adolescent feelings of rebellion, dissatisfaction and confusion?

All the elements are here for a one-of-a-kind musical experience, but everything would be wasted if not for this phenomenally talented cast, from Steel Burkhardt, whose Berger gets the audience ready for a night of in-your-face theater with some improvised crowd interaction and a silly striptease; to Remillard’s endearing Claude; to Caren Lyn Tackett’s knockout Sheila. The Pantages hasn’t been graced with a cast this good since “Wicked.” It’s nearly two-and-a-half hours of straight song, and no one so much as takes a breath.

Normally, breaking the fourth wall comes off as either kitschy or, worse, a desperate ploy to connect with the audience. It may be a little of both with “Hair,” but it’s handled so openheartedly and shamelessly that it becomes essential to the experience. Actors give out flowers and hugs, crawl over seats and lead the crowd in lots of clapping. None of it gets tiring, not even a little. 

But it might if these kids weren’t so totally into this experience themselves. In addition to the principals, Kacie Sheik is hilarious as the pregnant Jeanie, and Josh Lamon gets the most laughs of the night out of his performances (saying any more would spoil the fun). Look forward to anything Phyre Hawkins’ diva Dionne sings, along with Remillard, whose “Where Do I Go” is shattering. The only shame is that Remillard doesn’t get more songs with Burkhardt. As best friends, maybe more, their relationship is the sweetest of the show.

Amazingly, the way “Hair” deals with issues of race, sexuality and drugs feels as relevant as ever, even if the politics are old-fashioned. But then, we are fighting our own version of the Vietnam War today, so the pacifistic undercurrent retains its controversial edge — even if mandatory conscription is no longer an issue.

But more than its messages and its politics, “Hair” is everything a musical should be, and even more effective than its successors, like “Rent” and “Spring Awakening.” This is particularly exciting for the Pantages, which is finally back on track after a few duds earlier in the season.

It must have taken some courage to revive a musical as groundbreaking in its day as “Hair," and real creative talent to do it with such aplomb. Hats off to these creators. Because of them, hippies are cool again, and the world is a sunnier place.  

Reach Senior Arts Editor Jason Kehe here.