In theaters

HAIRSPRAY. Directed by Adam Shankman, written by Leslie Dixon, 115 minutes, rated PG.

Adam Shankman’s new musical, “Hairspray,” is one of the year’s best comedies, which is a surprise given that Shankman directed “The Pacifier” and “Cheaper by the Dozen 2,” each of which put a flop in the box office’s flip.

Not so with “Hairspray.”

Based on the hit Broadway show by way of John Water’s 1988 camp classic movie (look for Waters in a fleeting, flashing cameo), the film is expertly conceived, fun and infectious.

If you need a good laugh, this is your movie. Though it runs nearly two hours, the film is a juggernaut of kinetic energy. It never lags, which is at once a testament to Shankman, who also choreographed the elaborate dance sequences, as well as to screenwriter Leslie Dixon and to the cast, which for the most part is perfect.

In the lead is newcomer Nikki Blonsky as Tracy Turnblad, the impossibly perky, plus-sized Baltimore lass who is so enthusiastic about her city, she begins the show waking on the right side of the bed, dancing out of her house and down the streets while belting out “Good Morning, Baltimore.”

It’s a song whose lyrics not only suggest this smiling wonder teen is a force to be reckoned with, but also that at some point, all that we love about her -her beaming naivete, as well as her bottomless openness and kindness – will be challenged.

That challenge comes early. The film is set in 1962, with the country still coming to terms with the ramifications of segregation and integration.

Those are serious subjects to explore, so it’s to the movie’s great credit that it manages to make you feel just how serious without ever sacrificing the film’s mischief and fun. Chief demon in the proceedings is Michelle Pfeiffer’s Velma Von Tussle, with the actress steamrollering out of a five-year retirement to claim the screen as a vicious television station manager who will stop at nothing to make sure that her miserable daughter, Amber (Brittany Snow), wins the upcoming Miss Teenage Hairspray pageant.

Velma also is working to rid her station’s hugely popular dance show, “The Corny Collins Show,” of its Negro Day, in which Baltimore’s black youths are given one day a month for their own televised dance show.

As far as Velma sees it, keeping the station white also will keep it clean, and this whole Negro Day business hardly is doing the job.

So, yes, we despise her, so much so that when this racist gets hers, as you know she must when Tracy joins her black friends and Motormouth Maybell (Queen Latifah) in an effort to make “Negro Day every day,” it’s one undoing that’s deliciously handled and deserved.

Beyond the amazing Blonsky, whose unflagging energy should be canned by Red Bull, “Hairspray” also scores with performances by Zac Efron as Amber’s popular boyfriend Linc Larkin, who digs Tracy’s moves as well as her curves; Elijah Kelley as Seaweed, who opens Tracy’s eyes to black culture and who sweeps Tracy’s lollipop-sucking girlfriend, Penny Pingleton (Amanda Bynes), off her feet; James Marsden as the toothy Corny; Allison Janney as Penny’s Bible-thumping mother, Prudy; and Taylor Parks as Seaweed’s sister, Little Inez.

Having seen the Broadway show with the original cast, it’s hard not to miss Harvey Fierstein as Tracy’s robust mother, Edna, a large-sized laundress hooked on food and saddled with self-esteem issues. Likewise for Divine, who was Edna in the original movie. But John Travolta, who assumes the foam padding this time around, can’t be dismissed.

Unlike Fierstein, who came to the role charged with enough mince and vinegar to play to the back row, which he did with bravura, and Divine, who was the real thing – a drag queen offscreen as well as on – Travolta’s performance is a shift. His Edna is sweet, soft-spoken and shy, with the actor playing the part with barely a wink that it’s John Travolta under all that makeup.

As such, for purists, this particular man in the fat suit might not suit, but for mainstream audiences, for whom the movie is targeted, Travolta likely will win plenty over.

Helping him to that end is Christopher Walken as Edna’s husband, Wilbur, who shares with her a dance and a song that’s one of the film’s highlights.

The song is called “You’re Timeless to Me,” which was written by the gifted Scott Wittman and Marc Shaiman, and which, given the film’s themes of acceptance in a world that continues to resist it, easily could speak for the movie itself.

Grade: A-

Visit www.weekinrewind.com, the archive of Bangor Daily News film critic Christopher Smith’s reviews, which appear Mondays and Fridays in Lifestyle, weekends in Television as well as on bangordailynews.

com. He may be reached at Christopher@weekinrewind.com.