The glittering ascent and gaudy real-life crash of Pentecostal preacher Aimee Semple McPherson may not form the neatest of dramatic arcs, but there’s transcendence enough in Carolee Carmello’s soaring star-turn to redeem most of the sins of Saving Aimee, Signature Theatre’s rafter-rattling new musical.

From its opening number—a rouser in which Sister Aimee fends off a prosecutor’s charges of fraud and adultery by popping a few pills, plastering on a headlamp smile, and urging her flock to “Stand Up!”—this show yearns for the promised land of Broadway, and in Carmello it has the sort of charismatic leading lady who might well take it there.

It does not, just yet, have a second act to match its star’s fervor, and composers David Pomeranz and David Friedman have taken some odd side trips musically (a boozy Irish jig on a tramp steamer, for instance) to inject variety into a score they’ve overstuffed with keening anthems. But lyricist/librettist Kathie Lee Gifford (yes, that Kathie Lee Gifford) has found her way around hurdles—a story spanning 35 years, polarizing religious content, a possibly schizophrenic heroine whose ministry still boasts millions of followers—that might well have tripped up more seasoned theater artists. And Eric Schaeffer’s staging balances the heroine’s spirit with enough flesh that he’s serving up the same racy entertainment value that kept the faithful flocking to Aimee’s Angelus Temple through the 1920s.

This is, let’s note, an aspect of the story that’s tailor-made for musical retelling. Sister Aimee’s sermons got so showbizzy that detractors accused her of going Hollywood. Her weekly biblical extravaganzas played to SRO crowds in a 5,000-seat temple (John Wayne got one of his first acting jobs there) even before she became the first female evangelist to get a radio license.

None of which would count for much if we didn’t get a sense of who Aimee is, so the show leaps back from the stentorian prosecutor (Andrew Long) in the courtroom to show us Aimee as a rebellious teen who fought against her strict religious upbringing, leapt into marriage with a charismatic holy-roller, and very nearly prayed herself to death before forming her own religious movement.

Schaeffer’s staging works such wonders with these intimate early moments that it’s almost disappointing when life takes Aimee into more conventional showbiz territory—a New Orleans brothel, say, where she converts trash-talking Madam Mom (E. Faye Butler) into her ministry’s mother hen. Soon Aimee’s cream-colored gowns have gone from demure knee-length cotton to sparkly floor-length satin (exquisitely crafted by designer Anne Kennedy), and she’s headlining campy Bible pageants (which will doubtless prove even campier on a Broadway budget). After that, it takes Aimee having a complete nervous breakdown to cool things down to the point that you remember these folks are real people.

Actually, that’s not fair. Gifford’s script never camps them up; Aimee’s biography does—and that ends up being this faithfully faith-based musical’s chief problem. Life handed Sister Aimee a crummy second act. She got all scattered at the end and, perhaps inevitably, so does her show.

But lordy, does it go there stylishly. Jenny Cartney and her 13-piece pit band provide a joyful noise big enough that microphones are required for the singers even in Signature’s intimate space. Walt Spangler’s revival-hall setting can’t seem to stop rearranging itself, bannisters sliding one way, staircases another, as Chris Lee’s lighting paints their whitewashed planking with projected headlines and Bible verses.

Skittering out of the way are Butler, belting the gospel as that Madam who gets religion, Florence Lacey warbling sweetly as Aimee’s common-sensical nutcase of a mom, and a trio of male chameleons doubling as all the men in Aimee’s life. Portly Ed Dixon morphs from Aimee’s affable dad into a fiery evangelical rival; dashing Steve Wilson seduces Aimee’s spirit as a smooth preacher then seduces her flesh as a sexy cad; and Adam Monley finds the charm in a devoted accountant who weds her and the smarm in a married broadcaster who beds her. And Carmello’s full-voiced, ethereally anguished Aimee anchors them all—smart, fervent, and achingly lovely.

Although life didn’t grant Sister Aimee a big finish (she died of a barbiturate overdose), a musical needs one, so Schaeffer sends Aimee off with a lighting effect that might as well be beamed straight from heaven, and then reprises the opening number, “Stand Up,” during the curtain call. At the final preview, despite a set malfunction that forced some improvised reblocking at the last moment, the audience didn’t need to be cued.