Steve Martin’s ‘Bright Star’ changed this actor’s life. Now, she’ll say goodbye to it in Salt Lake City.

“Very bittersweet” is how Carmen Cusack describes her emotions as she heads to Salt Lake City to perform the last act of her career-changing role in “Bright Star, ”Steve Martin and Edie Brickell’s Americana musical.

“If you knew my story, you’d have a hard time believing me,” Cusak’s character sings in the musical’s opening number. “You’d think I was lying / Joy and sorrow never last / I’ll die trying not to live in the past.”

Those lyrics have deep emotional resonance for the actor, who earned a Tony Award nomination for originating the role in her Broadway debut. “Simply gorgeous,” The New York Times raved about Cusack’s performance.

Cusack’s long coming-to-success story and her family background add layers of emotional weight to her performance in “Bright Star,” which plays at Pioneer Theatre Company on Jan. 12-27. The show’s mini-tour, a co-production between Pioneer and Los Angeles’ Center Theatre Group, is an unusual partnership between Broadway producers and regional theaters, according to PTC artistic director Karen Azenberg.

Also notable is the musical’s bluegrass-tinged score, which has the feel of a living-room jam session, with its unusual-for-Broadway instrumentation featuring banjos, fiddles and accordion notes. “Families sit around and play music here,” Azenberg says, adding that the way the story explores family dynamics should resonate with Utah audiences.

Cusack describes the score as “Americana with bluegrass notes,” laughing as she admits the influence of the Food Network show she was watching before this phone interview. “Bright Star” is a story about teen pregnancy, about loss and overcoming loss. “To me, it’s a dark Southern Gothic story,” Cusack says. “That’s what I related to, because it hits your heart, and it turns it upside down several times.”

The musical premiered at San Diego’s Old Globe Theatre in 2014, moved to Broadway in February 2016, then closed several months later. On Broadway, “Bright Star” was noted for its gentle spirit and sentimental story, which for all the firepower of its famous musical collaborators was overlooked in a theatrical season crowned by “Hamilton.”

Cusack plays Alice Murphy, a 37-year-old Southern magazine editor in 1946, as well as the character’s dreamy, feisty 17-year-old self in flashback scenes set in 1923.

She's sensational in the role, says Azenberg, who is one of Utah’s handful of Tony voters. Her performance is “skilled and heart-wrenching and charming and appealing, all those things you want out of a star turn,” Azenberg says.

Cusack had been working with creators since the show’s first reading in 2013, but assumed she’d be replaced by a star if the musical transferred to Broadway.

In the early stages, the show’s writers didn’t realize exactly how closely the actor’s background paralleled that of her character, as she was the daughter and granddaughter of impoverished teen mothers. “My mother had me when she was 16,” Cusack says. “I can only begin to imagine the fright of that, of other people trying to tell you what to do with this life that is now in your body.”

The authenticity of Cusack’s experience became hard-wired into the story, as showcased in her character’s cathartic 11 o’clock number, “At Long Last,” which was written for her voice.

“Edie got very inspired by some of the things I could do vocally,” Cusack says. “She wanted to broaden the range and make it bigger, writing music to use the vocal style and qualities I have, which is such a luxury for a performer.”

“When I heard what she could do, I was inspired to sit at the piano and write songs that would allow her voice to soar,” Brickell told The New York Times in 2016. Martin added: “Scenes and songs were written knowing that she could handle them.”

Previously, Cusack had hustled to support herself for years, never quite breaking through as a performer. She dropped out of college to work as a singing waitress and on cruise ships. On national tours, she stepped into big roles after the stars moved on, playing Christine in “Phantom of the Opera,” Fantine in “Les Misérables” and Nellie Forbush in “South Pacific.”

In her first time performing in Salt Lake City, she’ll be the star who is moving on after the run ends. Now, the actor says, she has the luxury of turning down roles knowing other opportunities will come.

Cusack says she was grateful to return to the show after its Broadway run, as the creative team (including director Walter Bobbie, choreographer Josh Rhodes and music supervisor Peter Asher) worked with the cast to smooth transitions and further focus the show.

Creators and cast members hope the mini-tour will extend the musical’s life. “The show has an effect on everybody, but particularly on mothers,” says Patrick Cummings, who plays Jimmy Ray Dobbs, the boyfriend of the younger Alice, after understudying the role on Broadway.

On tour, he has worked to bring more goofiness to the character, underscoring the playfulness and witty sparks between young Alice and Jimmy Ray. His character ages 20 years over the course of the show, which is only one of the role’s challenges.

Jimmy Ray’s big number, “Heartbreaker,” is a heartbreak to perform. “It weighs heavy on me every night,” Cummings says, due to the range of emotions the character processes, in front of the audience, through the song.

During the Los Angeles run, Cummings thought the emotional stress of his character’s story was beginning to show up in his body, via random infections and a serious ankle injury. He learned to channel those emotions into his performance as he watched Cusack.

She’s a “tour de force” in the role, Cummings says. “There’s a magnetism to her when she’s doing this, whether it’s a light scene or a heavy scene, it’s undeniable. She has this extra cylinder that she’s firing on while performing this piece. I think it’s just in her. It’s in her bones, every part of this role.”