‘Sister Act’ musical at Mercury Theater is positively heavenly

“Sister Act” is musical theater comfort food. It makes no intellectual demands. The songs are eminently hummable.

And the plot is markedly inane: When mobbed-up nightclub singer Deloris Van Cartier accidentally stumbles onto a murder scene, she’s forced to hide in a struggling Philadelphia convent. Shenanigans ensue.

Based on the 1992 movie of the same name, the musical, running through Jan. 2 at the Mercury Theater, goes down as easy as cotton candy. But it’s cotton candy as served by a Michelin-starred restaurant.

Directed by Reneisha Jenkins, “Sister Act” hinges on questions with obvious answers: Can Deloris (Alexis J. Roston) turn a bevy of tone-deaf sisters into a supergroup that’ll pack the pews enough to save their church from closing? Will the endlessly disapproving Mother Superior (Jane Grebeck-Brewer) come to appreciate Deloris’ flashy ways and craven desire for cheesesteak? Will the nuns zhuzh up their habits by covering them in sparkles? Does anything rhyme with “transubstantiate”? Can nuns credibly rap?

Spoiler alert: This is comedy, not tragedy. Verily does it follow that in less time than it takes to deliver your average homily, Deloris has the nuns singing in righteous harmony and shaking it “like Mary Magdalene” (Glenn Slater’s lyrics are wholly hilarious as they pivot between pious and party).

Alan Menken’s score draws on the sacred and the profane, moving from hymn to hedonism without missing a beat. The songs aren’t complicated, but music director Diana Lawrence has the cast taking that simplicity and rendering it showstopping. Bookwriters Bill and Cheri Steinkellne and Douglas Carter Beane fill the space between the music with humor — including a narcoleptic shout-out to Barabbas.

As Deloris, Roston owns the stage from the opening number through the finale. Her nightclub banger “Take Me to Heaven” is a star turn, and her earnest delivery of the 11th-hour title tune is a moving ode to female friendship.

Brett Beiner Photography

Grebeck-Brewer makes an adequate foil as an old-school Mother Superior who sees cheesesteak as a stepping stone toward Sodom and Gomorrah levels of debauchery.

The gangster trio (Austin Nelson Jr., Marcus Jackson and Ruben Castro) featured in “Lady in the Long Black Dress” delivers Barry White-smooth vocals paired with foxy moves (excellent work by choreographer Christopher Chase Carter) worthy of 1970s “Soul Train.”

Which brings us to Gilbert Domally as Eddie the detective. Domally’s “I Could Be That Guy” will tug on your heartstrings with its sweetness while simultaneously knocking your socks off with Carter’s timeless, groovy moves.

There are also not one but two marvelous costume reveals, courtesy of Marquecia Jordan’s tearaway creations.

Finally, let’s take a moment for the spiritual journeys of Monsignor O’Hara (Ed Kross) and Sister Mary Robert (Isabella Andrews). Once the monsignor’s sequined vestments appear in the second act’s “Fabulous Baby” reprise, Kross makes the stage his catwalk, stomping and prancing like he was just crowned America’s Next Drag Superstar. When Andrews’ Mary Robert steps into the light for soaring anthem “The Life I Never Lived,” the sound is positively heavenly.

Jenkins’ cast isn’t the most polished. But the actors bring joy and funk to spare to “Sister Act.” That’s all the show needs. Amen.