One of the key moments in "Hairspray," the outgoing and supersized Broadway musical of the 1988 John Waters film, comes in the second act when heroine Tracy Turnblad, thrown in jail for protesting the fact that whites and blacks can't dance together on local TV, finds herself in solitary confinement. Plump and relentlessly optimistic, Tracy is one of those larger than life characters who's nearly perfect for the big, broad confines of a musical spectacular. She can raise your spirits just by bouncing on stage. Despite her humble upbringing and notable weight, Tracy is convinced that she can have it all: the hunky guy who has captured her heart; fame and fortune as a dancer; and even a slightly less racist world.

Behind bars, she stands alone on stage -- one of the few intimate moments in this non-stop cheery show -- and sings:

I'm all alone, my heart has grown, but it's broken, too.
This morning life was a Baltimore fairy tale, now I can't make bail.

In a way, this is a moment that can make or break this show. If your heart goes out to Tracy -- if you truly believe in her power to change the world -- then "Hairspray" is a glittering, bright and happy dose of good cheer. If not, it turns silly and soppy.

The national touring production that opened Saturday at the Saroyan Theatre (and continues for two more performances, at 2 and 7 p.m. today) boasts a first-rate Tracy. Brooklynn Pulver is a hurricane of enthusiasm on stage. Bouncing merrily along to the beat, she never misses a step. And when it comes time for her "Good Morning Baltimore" reprise in jail, she nails the key acting moment in the show, setting up the fun and frenzy of what's to come.

However, her delightful performance -- as well as several others -- was compromised by substandard sound quality in this show. The most prominent members of the "Hairspray" company should not include the percussionists, but in the opening matinee Saturday performance, that was the case. Perhaps it was where I was sitting -- to the far right side in an orchestra seat -- but a lot of the show sounded like good-natured mush. Lyrics were almost impossible to decipher in many of the songs. In the number "The Nicest Kids in Town," Corny Collins (played by Jarret Mallon), the dance-show host, was almost incomprehensible. So was Seaweed J. Stubbs (Christian White), the black high schooler who introduces Tracy to a new kind of dancing, in "Run and Tell That."

If I didn't know this show by heart (which I confess I do), it would have been difficult to understand many of the lyrics, including ones that are key to the plot. Even the wonderfully peppy finale, "You Can't Stop the Beat," was threatened by bad sound. Comparatively speaking, the recent touring production of "Aida" sounded crystal clear. I don't know if the fact that this is a non-Equity tour has affected the technical aspects of the production, but one thing is clear: A greater level of expertise or equipment is needed, soundwise, to give a show like this the production it deserves in the Saroyan.

Still, this "Hairspray" is a dancing frenzy, and the company is slick and sure on stage. Jerry O'Brien, as big-momma Edna Turnblad, plays it a little straighter (if that's possible for someone picking up the role originally played by Divine in the original movie) than Harvey Fierstein on the Broadway cast album. He has a sweet and loosey-goosey scene, played with husband Wilbur (Michael Walker) with the song "You're Timeless to Me," that nearly steals the show. Alyssa Malgeri is a standout as Tracy's best friend, Penny Pingleton. And Angela Birchett's' Motormouth Maybelle belts it out with style and volume in "I Know Where I've Been."

The set is reasonably close to the original Broadway production, if slightly scaled down and a little less full of spectacle in the finale. The choreography is high-caliber.

"Hairspray" is meant as good-natured fun, but it also tries to be issue-oriented. It almost bites off more than it can chew with both its racial-equality message and the plus-size-girl-as-leading-lady storyline. It's more successful with the plump-is-beautiful theme, but it's still nice to see a show like this trying to raise racial awareness.

And after a whopper of a second-act, led by a Tracy on fire, the show can't help but end on a high note. It isn't every day that you can see the world's biggest can of hairspray in Fresno.