At a well-known and much-frequented L.A. nightspot, John Waters’ cult classic film Hairspray plays on each of the LCD monitors hanging within the room. As patrons stand, mesmerized at the sight of a bouffant-clad Ricki Lake shaking what her mama gave her, it’s surprising how well this film holds up since its initial release nearly 20 years ago.

Now, the campy tale of a fat Jewish girl from Baltimore dancing her way into the hearts of many takes a third turn at bat with its latest inception, New Line’s musical, Hairspray.

At the nucleus of the project is its 18-year-old star, Nikki Blonsky. She plays dancing queen, Tracy Turnblad – the role originated by Lake and reprised for Broadway by Marissa Jaret Winokur.

Blonsky was working at an ice cream shop in Long Island when she got the call to suit up for her big screen debut. However, from the moment she sent her audition tape in to the film’s producers, it seemed that destiny already had a hand in this young star’s life.

“Once I saw Nikki’s audition, I immediately put her on my list,” recalls Adam Shankman, Hairspray’s producer, director and choreographer. “I’d watch a few others, and then I’d watch hers again. Finally, we all just recognized the fact that Nikki was Tracy.”

Blonsky takes to her role like a fish to water. Her version of Tracy has a lot more soul than before. It also appears that Blonsky’s upbringing bears strange parallels to that of her character.

“I was made fun of terribly at school because of my shape and because I’m short,” she confesses. “I think it definitely made me a stronger person.”

That spirit is the fuel that entwines every character in Hairspray. Each of them is gifted with something that they believe in, a strong moral conviction in which they are willing to fight tooth and nail.

Which brings us to Negro Day. For some, that’s a code name for Martin Luther King Day. For others, it’s Sucker Free Sunday on MTV. But in Hairspray, it’s the uncredited star of the show.

Here’s the rundown: a racist local socialite, Velma Von Tussle (Michelle Pfeiffer) and her uber-blond daughter, Amber (Brittany Snow) plot and scheme to keep the local “Corny Collins Show” segregated. Since Velma is the station manager of the channel it airs on, and Amber is its star dancer, integration seems impossible – even though Corny himself (James Marsden) wants it.

Meanwhile, Tracy – with her negative social status and full figure – is determined to be cast on the program. Through a chain of events, she takes a walk on the dark side, befriending several black kids from her school.

Most of her new friends are featured dancers on Negro Day at the “Corny Collins Show.” With their blessing, she learns from them a provocative dance that she uses to ultimately wind up on the program.

But Tracy isn’t having the segregation of the white kids from her newfound buddies. She spearheads a campaign for the rights of the ethnically diverse as well as the chubby.

“High School Musical’s” Zac Efron plays the dreamy – and socially conscious – Link. He is the boy that starts off betrothed to Amber, but later makes a beeline for Tracy.

Snow, who was last seen in John Tucker Must Die (2006), serves up laughs and a whole lot of “No, she didn’ts!” as an evil teen queen – a far cry from her usual girl-next-door roles.

Comedienne Amanda Bynes is also funny as Tracy’s best friend, Penny Pingleton. She is a dorky and sheltered girl, with a bible-toting mother who won’t let her get away with anything.

Bynes’s love interest in Hairspray is newcomer Elijah Kelley, who plays Motormouth Maybelle’s sexy son Seaweed. He and the rest of the cast perform a brilliant soundtrack written by Scott Wittman and Marc Shaiman (who wrote bawdy tunes for Southpark: Bigger, Longer & Uncut). In light of all the recent lapses in political correctness from stars like Michael Richards (“Seinfeld”), Mel Gibson and Isaiah Washington (“Grey’s Anatomy”), it’s only fitting that the next generation of Hollywood takes a stand to drive home the importance of tolerance. Projects like Hairspray are a hilarious way to way to open up that dialogue and effect some much-needed change.

Hairspray releases in theaters July 20.