Theater

Mary Bridget Davies channels Janis Joplin in new B’way show

“I was the loudest baby in the nursery,” says Mary Bridget Davies. “My parents have pictures and, literally, the whole photo is a mouth!”

Who better to star in “A Night with Janis Joplin”?

At a sneak peek of the show this summer, Davies sang for a group that included Joplin’s younger siblings. From her first, wrenching note of “Cry, Baby,” she made you believe in reincarnation.

Laura Joplin, the late singer’s sister, seemed to. “I feel lucky,” she told The Post. “Who else gets to see their sister come back and celebrate with her?”

That celebration was a long time coming. It’s been 43 years since the raspy singer from Port Arthur, Texas, died in a Hollywood hotel room, shot full of whiskey and heroin. She was 27.

Janis Joplin, 1970Getty Images

“I really do think she’s still around,” says Davies, who channels Joplin six nights a week at the Lyceum (Alison Cusano plays the matinees through Oct. 16; Kacee Clanton steps in after). “I’ve read her letters, and there are a lot of parallels in our lives.”

Drugs and southern Comfort aren’t among them — Davies prefers vitamin shakes — but both were raised on the blues. Growing up in Cleveland, Davies loved watching an old VHS tape of Etta James, and jumping up and down, screaming along, to Joplin’s “Piece of My Heart.”

Like Joplin, she battled bad skin and bullies. Davies’ big break came at 21, when she reached out to Sam Andrew, whose Big Brother and the Holding Company — Joplin’s old band — was coming to Ohio.

“I wrote him and said, ‘You’re playing close to my hometown. I’m a singer, and I’d love to meet you.’ He wrote back and said, ‘Sure!’”

She showed up at the club and, after she met the band, Andrews asked Davies if she’d like to get up and sing “Me and Bobby McGee” with them. Yes, she would. A flurry of gigs followed, with Big Brother and other bands.

About a year or so later, Davies and her mother came to New York to see the off-Broadway “Love, Janis” at the Village Gate. “My mom turned to me and said, ‘Could you do that?’ I said, ‘Certainly!’ But there was no way I could have played Janis when I was 22. I just didn’t have enough life experience.”

Many gigs, hotel rooms and a divorce later, she did. And when “A Night with Janis Joplin” played out of town, Davies learned even more about the woman she was playing.

“Bobby Neuwirth, who wrote ‘Mercedes Benz’ with her, pulled me aside in Pasadena [Calif.] and told me stories,” Davies recalls.

Joplin, Neuwirth said, had a salty, Mae west-like sense of humor, but was also “high-brow.” Backstage, she was often reading — Edith Wharton, Gertrude Stein and the Fitzgeralds, F. Scott and Zelda. Her favorite Beatle was George Harrison; she even named her mutt for him. and no matter how much Joplin put down her hometown — where, she said, “You wore your hair in a flip and kept your mouth shut” — she always wrote letters home.

That’s not the only way Davies connected to Joplin. Years ago, Davies says, she and her astrology-loving mother went to Sedona, Ariz., to have their auras read. Someone took a photo of Davies and in it, alongside her orange aura, is an orb that the aura reader called her “spirit guide.”

“Yeah, right,” she scoffed. “what is it — a wolf?” No, she was told: “It’s a woman, and she [did] what you’re doing now. She’s here to make sure you don’t make the mistakes she made.”

Years passed. and then, after Davies sang with Joplin’s band, that forgotten photo fell from a book. Suddenly Davies knew.

“It’s her!” she says. “It’s Janis. who else could it be?”

THE JANIS WANNABEES

Ever since Bette Midler wailed her way through “The Rose,” a fictionalized 1979 drama based on Janis Joplin’s life, moviemakers have sought a Joplin of their own.

RENEE ZELLWEGER: Fans scratched their heads over this rumored casting, which never came to fruition.

PINK: In 2004, the singer was reported to be next in line to play Joplin.

ZOOEY DESCHANEL: After Pink dropped out, the actress prepped for the role for three years, to no avail.

AMY ADAMS: Director Lee Daniels (“The Butler”) has chosen the star—who sang in “The Muppets” — for his biopic.

NINA ARIANDA: The “Venus in Fur” Tony winner is set to play Joplin for director Sean Durkin (“Martha Marcy May Marlene”).