Let the sisters sing.

Let them dance, rejoice and swell our hearts with a hymn of jubilant self discovery.

“Sister Act” is a lightweight confection built on great 1970s tunes, and Chanhassen Dinner Theatre’s production doesn’t resist that delicious fizz. However, director Michael Brindisi and a terrific cast accomplish something deeper, more fulfilling, in this story about sisterhood and transformation.

Chanhassen’s production took a while to find its legs on opening night but when it took off, it soared on the wings of Regina Marie Williams’ performance as nightclub singer/faux nun Deloris van Cartier

An intuitive actor, Williams is nimble, physically commanding, smart and willing to find whatever gravitas exists in a character. And she’s funny — really funny! Williams’ singing is savagely strong on “Raise Your Voice” and tender in “Sister Act.” In short, she is a giant among mortals, a judgment not intended to diminish her castmates but only to acknowledge that Deloris is the best role in the play and Williams takes full advantage.

For those without Wikipedia, “Sister Act” is based on the 1991 film starring Whoopi Goldberg. Deloris is a frustrated nightclub singer who witnesses her abusive boyfriend, Curtis, cap an associate in the alley behind his club.

She flees, and a sympathetic cop, who wants Deloris to testify against Curtis, hides her in a convent. Hijinks ensue as Deloris transforms a lifeless, but still faithful, bunch of nuns into a joyous chorus whose crystalline voices fill the church’s pews with people and bring it fame.

Brindisi has cast this show quite well — starting of course with Williams. She is not alone, though. Norah Long is just the best as Mother Superior, a role that seems written for her. Her humor is droll, her stage presence elegant and her voice effortless in such songs as “Haven’t Got a Prayer.” Long never cheats an audience and in this case her Mother Superior is a formidable foil for Williams.

Therese Walth’s Sister Mary Patrick is the exuberant spirit among the sisters, and the actor brings to the stage the same energy we saw in Chanhassen’s “Hairspray.” Andre Shoals does his best work at Chan as bad boy Curtis, growling his way through the smooth disco beat of “When I Find My Baby.” Kasono Mwanza and Keith Rice make nice work of their moments and every member of the nuns’ chorus deserves applause.

Reginald D. Haney plays “Sweaty Eddie,” the timid cop who is sweet on Deloris. Haney’s performance is shaded to caricature, as are Shoals’ Curtis and his hoodlums. That off-kilter style — almost a cartoon — balances the nuns’ earnest naturalism and gives the production some real swing.

These reasons and many others (such as Richard Long’s band serving up perfect slabs of ‘70s disco and soul) recommend “Sister Act.” Should you need only one, obviously it’s Williams’ show. Were you to allow me a second, I would offer Britta Ollmann’s portrayal of Mary Robert, the shy and confused sister who finds her voice with Deloris’ encouragement.

I reviewed Ollmann as a kid in 1999 and have watched her over the years. To see her now as this great adult artist who captured the audience Friday was a little overwhelming. I have a hunch, though, that I was not the only one verklempt after she sang “The Life I Never Led.” Ollmann’s earnest innocence and voice make Mary Robert the sweet heart of this show.

“Sister Act” can be fluff, but Chanhassen’s production shows what happens when actors are willing to play this stuff as a triumph for the underdogs — the little people with big dreams. We all win in that world.