Carmen Cusack is don’t-look-away-amazing in “Bright Star,” Steve Martin and Edie Brickell’s Southern-rooted Broadway show now playing at Pioneer Theatre Company.

Cusack’s life experience — her joy and sorrow — deepens and enriches her remarkable star turn as Alice Murphy, a 1940s magazine editor with a painful past. Cusack’s husky, rangey and richly textured voice makes the most of Martin and Brickell’s emotionally wrenching, but simple, tunes.

Her acting is nuanced and subtle, and she leads a crackerjack cast in this innovative partnership among Pioneer, Los Angeles’ Center Theatre Group and the show’s original Broadway producers. It’s particularly notable that the Salt Lake performances feature the last shows by Cusack, the Tony-nominated actor who created the role through workshops and its short 2016 Broadway run.

Friday’s opening-night performance was dedicated to the memory of Thomas S. Monson, the late president of The Church of Jesus Christ of Latter-day Saints, a former Pioneer Theatre board member.

I’m betting local theatergoers will be bragging about seeing this show for years to come. After opening weekend, tickets are outselling expectations, and “Bright Star” is expected to become the best-selling unknown musical to play on Pioneer stages.

Adding to the buzzy phenomenon are a handful of superfans who flew into town to follow the tour, says Kirsten Park, PTC marketing director. (The weekend’s rush lines were long; Park adds ticket availability is best for this week’s weekday shows.)

The ensemble cast and onstage musicians’ authentically rich performances, along with the earwormy appeal of Martin and Brickell’s bluegrass-inspired score, total more than the sum of the show’s parts. Walter Bobbie’s direction is underscored by the simple, innovative staging, with sets by Eugene Lee, costumes by Jane Greenwood and choreography by Josh Rhodes.

“Bright Star” delivers such an emotionally resonant experience that it allows theatergoers to forgive and forget the story’s flaws. The main plot point is played as sentimental farce, and the coincidences are too coincidental. In short, when you walk away from the theater, the story doesn’t hold up — although the song lyrics do.

Alice Murphy, the musical’s protagonist, is a sharp-tongued North Carolina literary magazine editor who finds herself swept up in encouraging Billy Cane (A.J. Shively, who created the role on Broadway), an earnest wannabe writer who has just returned from World War II. Alice’s idea of a good time is staying home cozying up to unnecessary adverbs and then cutting their heads off.

But as Alice is swept up in the postwar celebration, she flashes back to memories of herself at 17, when she was a feisty firecracker ready to explode out of her small town. When she falls for Jimmy Ray (Patrick Cummings), the mayor’s son, their love affair threatens to ruin their futures.

(Courtesy photo by Craig Schwartz) Carmen Cusack and Patrick Cummings in Steve Martin and Edie Brickell's "Bright Star," directed by Walter Bobbie. The musical plays Jan. 12-27.

The staging of that first flashback unwinds simply and beautifully onstage, inviting theatergoers into the story as the actor strips years away from her character before our eyes.

Cusack is terrifically girlish and flirty with Cummings’ young Jimmy Ray, turning their duet “Whoa, Momma” into a masterclass of chemistry. That chemistry becomes the foundation for the beautifully tragic duet “I Had a Vision.”

(Courtesy photo by Craig Schwartz) Carmen Cusack and Patrick Cummings in Steve Martin and Edie Brickell's "Bright Star." The musical will play at Pioneer Theatre Company Jan. 12-27.

It’s hard to imagine the emotional weight on Cusack in performing the wrenching “Please Don’t Take Him” eight times a week. But her showcase, the jubilant gospel anthem “At Long Last,” is a wonderful dramatic payoff as it invites theatergoers to celebrate along with her character.

Notable, too, is the way in which the ensemble’s harmonies and movement add ballast to the story, as dancers flow through scenes while the action is unfolding. The set’s rundown mountain cabin serves as a stage for the onstage musicians, who, like the dancers, serve as a kind of Greek chorus, foregrounding and backgrounding the action.

(Courtesy photo by Craig Schwartz) Cast musicians perform in Steve Martin and Edie Brickell's "Bright Star." The Americana musical will play at Pioneer Theatre Company Jan. 12-27.

Martin’s trademark wry, sarcastic comedy notes are richly delivered by the team of Daryl and Lucy (Jeff Blumenkrantz and Kaitlyn Davidson), the know-it-all editors on Murphy’s staff. Shively’s Billy Cane and the girl-back-home, Margo (Maddie Shea Baldwin), have a convincing exuberance.

The musical’s themes, exploring how families betray their black sheep and little lost lambs, should have special resonance with Utah audiences. At last, “Bright Star” reminds us that it is love and hope that helps those daughters and sons forgive.