Mary Bridget Davies was playing Janis Joplin long before she stepped on stage as the legendary Pearl at the Cleveland Play House's Allen Theatre.

As a little girl, she jumped onto her parents' green corduroy couch in Fairview Park and wailed "Piece of My Heart" like a banshee.

At 23, she dressed as the late blues rocker for Halloween. Someone took a picture. Davies had all the trappings down cold: the trademark feather boa erupting from her hair like a riot of angry, multi-colored birds; the round, over-sized sunglasses bordered by rhinestone, eclipsing her small, pale face. Rings on every finger, she's throwing a punch with a bangle-covered arm.

Now, in the classic story of understudy turned star, she's wowing sell-out crowds for seven performances a week in "One Night With Janis Joplin."

Davies recalled hearing this critique from a woman after a recent show: "You came out and I thought, 'She doesn't look like Janis Joplin.' And by the second act, I said, 'My god, that's Janis Joplin.' You just transformed."

Davies laughed at the memory. "That's my job -- to make you believe that that's who I am," she said.

Then, her smile faded and she was all business. "When I sing those songs, it's like the first time I'm singin' 'em. Because that's how she would've done it."

Mother really taught me so much about singing. It gave her so much pleasure. It was really my Mom who . . . got me to first understand and sing the blues.

--Janis Joplin in "One Night With Janis Joplin" by Randy Johnson

Mary Bridget Davies was barely out of the womb when she first heard "Summertime" from "Porgy & Bess," one of Joplin's favorite songs. Her mother would rock her to sleep singing the Gershwin tune.

She was born Aug. 30, 1978, eight years after Joplin died of a heroin overdose in a Hollywood hotel, to parents who loved the Blues. Her father, Brian, played guitar and sang for a blues rock band; her mother, Mary Ellen, collected albums by the greats: Bessie Smith, Dinah Washington, Etta James.

Music drifted through the Joplin household too. Every Saturday in Port Arthur, Texas, Dorothy Joplin would put on show tunes and her children, Janis, Michael and Laura, would clean house and sing, their mother giving them impromptu lessons.

"Put the endings on your words," "Support your tones from here . . .," she'd instruct. That's how young Janis learned to love "Summertime," a tune she famously adapted to her raspy freight train howl and made her own.

Mary Ellen Davies, a Joplin fan, would also sing the superstar's hits around the house. "I always did love Janis," she said. Mary Ellen had a microphone hooked to her stereo and would belt along with "Cry, Baby" and other Joplin staples.

She'd give the mic to the kids too. Not that Mary Bridget needed much encouragement. "She would just sing all the time," Mary Ellen said. "We could never get her to sleep."

At 12 or 13, she would practice on a Karaoke machine in the basement for singing competitions at the local Sheraton. At near glass-shattering volume.

"Can't you drop that note a little bit? What are you doin'?" Mary Ellen would shout.

At Fairview High School, Mary Bridget felt like an outsider, choosing the indignant approach Joplin took.

"I'm gonna be myself, I'm not gonna try to be the version of me that you like to try and fit in with you and your stupid friends," Davies said. "I'm gonna keep it real. That was her thing -- authenticity was very important."

And, like Joplin, Davies gave higher education a college try, with the same results.

"She hated it and quit to sing and so did I," Davies said. She began jamming at places like the Parkview Nite Club in Cleveland, where owner Norm Plonski recalled the Mary Bridget Davies Effect.

"When she sings it's like, 'Okay, let's quit talkin' and listen to this," he said.

Others noticed, too.

She always had "a big-ass set of lungs," said Cleveland Blues man Austin Walkin' Cane.

Jack Charlton, one of her early band mates in "Sinisin" and later, "Fraidnot," remembered a keyboard player who kept trying to replace Mary Bridget with other singers. "I said, 'We should name the band after Mary Bridget!" Charlton fired the keyboard player.

In 2001, in what would prove to be one of the most important trips of her life, Davies and her parents went to New York to see "Love, Janis," the Off-Broadway musical inspired by the Laura Joplin book. Even though Davies had little formal voice training -- something else she shared with Joplin -- she turned to her mother and proclaimed, "I'm gonna do that someday."

"Oh, man," Mary Ellen Davies thought. "Now you're getting way ahead of yourself."

Back in Cleveland, Davies found an address and fired off the Halloween photo of herself, inscribed with these words: "Are you ready for me yet?" She didn't expect to hear from Sam Andrew, the music director of "Love, Janis" and founding member of Big Brother and the Holding Company.

Some 30 years earlier, Andrew had been canny enough to hire Joplin, a Texas girl with a voice as big as the Lone Star State and a heart to match. When Joplin debuted with Big Brother at the Avalon Ballroom in San Francisco, she was 23. So was Davies when she sent Andrew her picture.

Along with the photo, Davies offered Andrew tapes and board mixes from her Cleveland gigs. He was charmed. It just so happened Big Brother would be in Ohio, at a spot called Angels' Saloon.

You're welcome to come, he wrote back. Bring your mom and dad.

She did, and the band invited her to sit in and do "Me and Bobby McGee."

"How was that?" she asked when she'd sung the last note.

"That was eerily familiar," bass player Peter Albin told her.

It's funny being on the road. You know how I can tell I'm in Cleveland? The walls at the Holiday Inn are green. . . That's it. That's what I see. It's a series of one-night-stands. There's that little period on the stage. . . Then there's television flat on our backs at the motel. Downtown nowhere. Checking in, checking out, lots of strange dressing rooms, too early at the airport, too late at the party. Glamorous, isn't it?

-- "Janis First Person" by Sam Andrew, Big Brother and the Holding Company

After their meeting at Angels' Saloon, Sam Andrew kept Davies' number handy. In 2005, he called looking for a horn player and a few other musicians to round out the cast of the road company of "Love, Janis," which was making a stop in Cleveland.

Davies, now married to musician Adam Constantine, had names at the ready, including Kristine Jackson, a gifted trumpeter and Ben Nieves, who played killer guitar, all friends from their days at the Parkview and other joints. The musical's director, Randal Myler, was also looking for a Janis.

"I said, 'When do we start?' Davies asked. "And Sam said, 'Oh, you still have to audition for the director.' "

Davies landed the role as soon as she opened her mouth. "I knew she would knock 'em dead," Andrew said. "Because I'd heard her sing."

She performed the show in PlayhouseSquare, then packed up for the tour. One of the stops was in Houston -- with Laura and Michael Joplin and a passel of Laura's old high school chums in attendance.

"No pressure!" Davies said.

In 2006, she started singing occasionally with Big Brother, accompanying the storied act on its European tours. That year also brought a Blues-sized heartbreak when she and husband Adam Constantine divorced, three years after their Vegas wedding.

"Anyone who knows us knows that we were just too young," she said.

Like Joplin and all blues artists, Davies channeled her pain into her product.

The Mary Bridget Davies Group, her new eponymous band of musicians from Kansas City, won second place in the International Blues Challenge in 2011, besting hundreds from around the globe. Constantine was competing with another group and watched as his ex got a standing ovation for her tune "Gettin' Stronger," a stirring number where she tells an old love, "I'm getting stronger the longer you stay away from me."

"Glad I could be of assistance," he told her after the set.

That song is on her new CD, "Wanna Feel Somethin'," available on dcbaby.com and itunes. It has been nominated for two Blues Blast Awards, which Davies likened to "mini-Grammys." (To cast a vote for "Wanna Feel Somethin' " visit http://thebluesblast.com/bbma/2012/12bbmavote.php).

The success of the disc proves "I'm not an impersonator," she said. "It just so happens that I do the same thing for a living that Janis did."

In May, Davies auditioned in New York to be understudy to the lead in a new musical called "One Night With Janis Joplin." During her tryout, Liza Minnelli walked in to visit her friend, writer-director Randy Johnson.

"That wasn't any pressure either," Davies said.

I'm not losing my voice. It's actually better than it's ever been. If I don't have to sing seven nights a week I can last forever. Hey, nothing's going to happen to me.

-- "Janis First Person"

In what has now become local theater lore, Cat Stephani, who originated the role of Janis in Portland, Ore., left the Cleveland production while it was still in previews. When "One Night With Janis Joplin" opened on Aug. 1, the headliner was Davies, the home-grown talent, belting out more than 20 vocal cord-shredding numbers and bringing down the house.

"I would see her every day in rehearsal and performance sitting there, watching the show and intently studying it," said Johnson. "I knew when I made the call she'd be ready. I had no doubts."

Cast members had to adjust to the switch, putting in extra time and giving up days off to learn to work with another Janis. On stage as in life, the lead singer "conducts" the band, controlling the transitions from one song to the next.

"The thing that can sometimes be difficult with a new person is you don't necessarily know their body language," said guitarist Ross Seligman. "That wasn't the case with Mary Bridget. It was really clear with her because she's so experienced fronting bands. We just all knew instantly what she meant."

And, though she's playing an icon, Davies is no diva, said Sabrina Elayne Carten, who stars as The Blues Singer, the embodiment of Joplin's influences.

"It was our first afternoon off and everybody was like, 'I can't believe we gotta go in there!' But Mary was gracious. Of course we had to come in, but she thanked us, where other people would say, 'Well you gotta be here so, whatever.' "

Andrew isn't surprised Davies is such a hit.

"She's very gifted," he said. "And she's done it a million times. . . this is a girl who has done all of those songs you heard many, many, many times in dirty little squalid clubs with 25 people in them and then 25,000 people the next night, in all kinds of conditions. She's definitely had the practice. But she was always good. She was born good."

At 33, Davies has already outlived the incandescent Joplin by six years. In her twenties, she had the passion to play Joplin, but not the maturity to protect her instrument. Now she knows that in order to sing like the legend, she's got to take care of herself.

"There's the part of me that's like, 'Let's go out -- Woooooooo! that was an awesome show." Then she realizes she has to do the same awesome show six more times in a week. So she heads home to Lakewood, calls her parents and hits the hay.

Making the smart choice hasn't always been easy, though.

I remember one of Janis's quotes," Davies said: While the boys in the band are hooking up with groupies," 'I'm standin' there with my hose run through waitin' for the manager to drive me back to the hotel.'

"How many times have I been there?" Davies said.

In the old days, she would buy a six-pack of beer, watch YouTube videos, pass out and do it again the next day. Fighting insomnia and loneliness, "I never did drugs -- but I drank enough to float the ark across the entire Atlantic ocean," she said. "But that's behind me now."

Being the star still involves sacrifice. Davies had to drop out of an upcoming Big Brother tour and dissolve the Mary Bridget Davies Group to lead the show.

For the record, her love life is looking up -- not great for writing the Blues but who cares? She's dating Chicago musician Michael Ledbetter, coming to the Beachland Ballroom Thursday. He's also related to the famed Leadbelly, an artist Janis loved.

Her newfound equanimity is paying off in the crowds flocking to see her commanding the spotlight with that feather boa in her hair.

"Mother really taught me so much about singing," Davies, as Janis, says from the Allen Theatre stage. "It was really my Mom who . . . got me to first understand and sing the blues."

In the audience night after night, Mary Ellen Davies knows her daughter is speaking those lines to her.