You’ll be happy to hear that the kids are all right. Quite a bit more than all right. Having moved indoors to Broadway from the Delacorte Theater in Central Park — where last summer they lighted up the night skies, howled at the moon and had ticket seekers lining up at dawn — the young cast members of Diane Paulus’s thrilling revival of “Hair” show no signs of becoming domesticated. On the contrary, they’re tearing down the house in the production that opened on Tuesday night at the Al Hirschfeld Theater. And any theatergoer with a pulse will find it hard to resist their invitation to join the demolition crew. This emotionally rich revival of “The American Tribal Love-Rock Musical” from 1967 delivers what Broadway otherwise hasn’t felt this season: the intense, unadulterated joy and anguish of that bi-polar state called youth.

Yes, I know there was a musical called “13,” about being exactly that age, that opened last fall, and that a lyrical revival of “West Side Story” is now playing to packed houses only a few blocks away. But what distinguishes “Hair” from other recent shows about being young is the illusion it sustains of rawness and immediacy, an un-self-conscious sense of the most self-conscious chapter in a person’s life.

Notice I did say “illusion.” Ms. Paulus and her creative team have worked hard at their seamless spontaneity. Karole Armitage’s happy hippie choreography, with its group gropes and mass writhing, looks as if it’s being invented on the spot. But there’s intelligent form within the seeming formlessness. And the whole production has been shaped in ways that find symmetry — and complexity — in a show that people tend to remember as a feel-good free-for-all.

“Hair” has a history of defying expectations. Gerome Ragni, James Rado and Galt MacDermot’s portrait of living low and staying high in the East Village was, by all accounts, a mess up to the day it opened for previews at the Public Theater in 1967, with a last-minute switch of directors and several wholesale restagings. It was not an obvious candidate for the Broadway transfer it made the following year (with a new director, Tom O’Horgan, and a streamlined book). But of course it ran and ran, for 1,750 performances, and became the last original Broadway musical to introduce more than a couple of Top 40 hits.

Its latest resurrection, however, may be the most surprising of all. “The show is the first Broadway musical in some time to have the authentic voice of today rather than the day before yesterday,” wrote Clive Barnes in The New York Times when “Hair” opened in 1968. “Authentic voices of today” tend to grow cracked and quaint with age. A 1977 revival, which ran for 43 performances, suggested that “Hair” was strictly a show for its time, not for the ages.

That there’s nothing of the museum — or, worse, of the vintage jukebox — about Ms. Paulus’s production isn’t because she’s reinterpreted or even reframed it. She does what Bartlett Sher did for “South Pacific” last year, finding depths of character and feeling in what most people dismissed as dried corn. It’s not so much what Ms. Paulus brings to “Hair”; it’s what she brings out of it, vital elements that were always waiting to be rediscovered.

Most important, she clearly knew early that “Hair” isn’t just a celebration of the counterculture it depicts. The young folks here who sleep, trip and protest together may spout the philosophy of “peace, love, freedom, happiness.” But, hey, they’re all mostly in the waning days of their adolescence, a time when moods swing wide and adulthood looms as a suffocating shadow.

The kids of “Hair” are cuddly, sweet, madcap and ecstatic. They’re also angry, hostile, confused and scared as hell — and not just of the Vietnam War, which threatens to devour the male members of their tribe. They’re frightened of how the future is going to change them and of not knowing what comes next. Acting out the lives of the adults they disdain (a charade at which Andrew Kober, Theo Stockman and Megan Lawrence are particularly expert) becomes a cathartic ritual.

Ms. Paulus vividly establishes the show’s essential dichotomy in the first number, when she brings two performers to center stage. On the one hand, there’s Dionne (Sasha Allen), who leads the anthemic “Age of Aquarius” with soaring spirits and unimpeachable authority; on the other, standing to Dionne’s right, there’s Crissy (Allison Case), with a scrunched-up face and contorted posture that read like a plea for help, shelter and attention.

They all want attention, of course. Who doesn’t at that age? At least except when you’re longing to be invisible, like Claude (Gavin Creel), a young man who’s about to be drafted, who leads the show’s most stirring songs of affirmation (“I Got Life”) and helplessness (“Where Do I Go”).

Though a less flashy and show-offy presence than his best friend, Berger (Will Swenson), Claude is the divided soul of “Hair.” At the Delacorte, Jonathan Groff, with his outsider’s wistfulness, seemed such a natural in the part that I was sure that the Broadway “Hair” would suffer from his absence. But the pure-voiced Mr. Creel, late of “Mary Poppins,” scruffs up real nice. That he seems more a part of the gang than Mr. Groff did somehow makes this Claude come across as more of a bellwether of the group, the one who’s most in touch with the ambivalence they’re all feeling.

Mr. Creel does not dominate the show; nor does the terrific Mr. Swenson, who finds an edge of cruelty and desperation in the grandstanding Berger; nor does Caissie Levy (an excellent new addition to the cast) as the earnest politico Sheila, the woman both men sort of love.

Every single ensemble member emerges as an individual, each with specific issues and knotty histories that no drug or slogan can resolve. (Even their nudity, and how they flaunt it, in the first-act finale, further defines them.)

After the show I couldn’t stop thinking about what would happen to Bryce Ryness’s sexually inchoate Woof; Ms. Case’s hopeful, fretful Crissy; Darius Nichols’s defiant, suspicious Hud; Kacie Sheik’s pregnant, cheerily adrift Jeanie; or Ms. Allen’s taunting, sensually assured Dionne. I could go on through the entire cast list.

Mr. MacDermot’s music, which always had more pop than acid, holds up beautifully, given infectious life by the onstage band and the flavorfully blended voices of the cast. Scott Pask’s exposed-wall set is the perfect playground for a world in which imagination (aided by chemical substances) provides the décor.

But of course no stage can contain the hormone-stoked exuberance of those who inhabit it, whether they’re yipping, unzipping or tripping, both merrily and scarily. Know that you may find yourself in intimate contact with various dancing, cajoling tribe members. They may give you daisies or leaflets. They may even ask you to embrace them. Not that you haven’t already.