That Baltimore's cinema transgressor John Waters made a PG-rated film in 1988 was shocking enough. But when his low-budget comedy Hairspray became an audience-friendly, Tony-winning Broadway musical in 2002, it was nothing less than mind-blowing. Now, in its third incarnation, Hairspray is a big-budget Hollywood song-and-dance romp, an irresistible piece of summer entertainment that offers the same satisfaction of recent movie musical hits like Dreamgirls and Chicago.

In its own mischievous way, the original Hairspray was subversive, giving a disarming spin to the very real and painful issue of segregation in 1962 Baltimore. The characters who take to the barricades in Waters' movie aren't activists per se, but earnest, music-crazy teens who can't comprehend why their local TV dance show has to separate the races. The 1988 Hairspray shrewdly used the authentic music, dances and wholesome atmosphere of the period to illustrate just how absurd that sort of narrow thinking looked in retrospect.

The musical, with spot-on pop songs by Marc Shaiman and Scott Wittman, takes the attitude of the original to a giddy new level. And, first with Harvey Fierstein on Broadway and now with John Travolta, it finds a way to honor another Waters tradition--a fully integrated leading role for a man in drag in the tradition of Waters' late, great muse, Divine.

Hairspray, of course, also embraces "fat power." Both Travolta's Edna Turnblad and her teenage daughter Tracy (newcomer Nikki Blonsky) are double-plus-size girls, lending another sort of outcast to the narrative mix. But while Edna is a housebound introvert, Nikki doesn't let her extra girth cramp her style. It certainly doesn't stop her from landing a spot as a regular dancer on her beloved "Corny Collins Show," to the vexation of the show's spotlight-hog, spoiled teen beauty queen Amber (Brittany Snow), daughter of bitchy, racist station manager Velma Von Tussle (Michelle Pfeiffer).

Tracy learns her killer dance moves while in detention with the high school's black kids, and she's outraged when Velma cancels the monthly TV "Negro Day" hosted by local record-shop owner Motormouth Maybelle (Queen Latifah). Helping to organize a march for dancers' integration leads to big trouble for Tracy, but everyone gets just what they deserve in the movie's big "Miss Teenage Hairspray" pageant finale.

Director/choreographer Adam Shankman's film gets off to a most impressive start with Tracy's opening number, "Good Morning, Baltimore," a joyous and funny mise-en-scène-setter that spans several blocks of the production's period-dressed Toronto set. (Watch for Waters' quick cameo as a flasher.) The movie's energy seldom flags, with showcase opportunities for every significant member of the cast. Pfeiffer, still looking gorgeous at 49, shows she hasn't lost the singing and dancing skills she so memorably displayed in The Fabulous Baker Boys; the great Queen Latifah gets two big numbers; and Travolta and Christopher Walken as Edna's doting joke-shop-owning husband ("This heart only beats for size 60") are given a delightful dance duet. The most dynamic member of this big cast, however, is newcomer Elijah Kelley as Maybelle's son Seaweed, who simply sizzles in his featured number, "Run and Tell That."

One of the draws and/or potential drawbacks of Hairspray is the vision of John Travolta in zaftig drag, and at first it seems like an easy novelty joke. But the actor seems to be working to find the vulnerable human being (complete with apparently authentic Baltimore accent) within all his elaborate makeup appliances, and the performance eventually wins you over. And it's fun to see Travolta dance again, even under these very special circumstances.

Blonsky isn't a knockout dancer (though she moves well for her size); her strengths are her big voice and the sunny likability she brings to Tracy. For teen and tween audiences, the bonus casting includes former Nickelodeon star Amanda Bynes, amusingly geeky as Tracy's best friend Penny, and High School Musical heartthrob Zac Efron as Tracy's crush Linc, who develops a liking for portly girls.

Shankman regrettably jettisons the real-life period dances that made the original Waters film such fun; his choreography is lively, but there's nothing as thrilling as the Madison line dance in the 1988 film. Audiences will still come out of the new Hairspray on a high, but they're advised to rent the '80s classic and see what pure Waters is all about.