'Rocky'

Margo Seibert and Andy Karl, the stars of the new "Rocky" adaptation on Broadway. (Matthew Murphy / Handout, Baltimore Sun / March 5, 2014)

A down-to-earth guy from a working-class city is determined to succeed in a tough business. Punching above his weight, he beats the odds and makes it into the ring, cheered on by a crowd that includes a woman who shares his modest roots and encourages his big dreams.

That's not just the scenario of the wildly popular 1976 film "Rocky." It also works as the art-imitating-art story line for the two Baltimore-area actors starring in the new musical version of "Rocky" that opens this week on Broadway.

The guy playing the title character is Baltimore-born Andy Karl, who knows a thing or two about a working-class background and building the stamina needed to compete in the spotlight. Much the same applies to Howard County native Margo Seibert, who portrays Rocky's girlfriend, Adrian.

"The underdog story of 'Rocky' is very true for Andy and myself," says Seibert, 29. "It speaks to us. Neither of us was formally trained. We worked our way up. It was a whole long process for the both of us, and I think that's part of who we are."

Each actor, armed with theater credits from this area, moved to if-you-can-make-it-there New York — Karl 20 years ago, Seibert in 2010 — hoping to find success. "Rocky" represents a major milestone for them: the first lead role for Karl on Broadway, the Broadway debut for Seibert.

The $16.5 million musical looks like it could be a contender, given the talent onstage and the pedigree of the creative team.

Sylvester Stallone, who originated the role of Rocky Balboa, is the producer; he also collaborated on the book with Thomas Meehan, whose Tony Awards include one for "Hairspray." The score is by Stephen Flaherty (music) and Lynn Ahrens (lyrics), who won a Tony for their work on "Ragtime."

There's has been a hot spotlight on the show since its first preview performance Feb. 13, when Stallone got into the ring during the curtain calls — Karl dropped to the floor and bowed to the uber-Rocky. The already enthusiastic audience went into overdrive. (Video can be found on the Internet.)

"You never heard an audience lose their minds like they've been doing at previews," says Karl, 39. "It's like you're at Madison Square Garden."

Tackling the role of the scrappy boxer has been a goal of Karl's since he heard about the musical in 2011. He lost out when the show ended up having its first staging in Germany (in German), but was ready when he learned about a New York production.

To prepare, he headed to the gym for boxing training (fight scenes in the musical involve some real body blows). The Rocky-like focus paid off.

"Just being offered the chance to do the role put this I'm-not-going-to-quit-no-matter-what idea in my head," Karl says. "I want to live up to that spirit, no matter how much my neck aches or back aches."

In addition to getting physically primed to head down the "Rocky" road, Karl has been drawing on some of his past to fuel his portrayal of a minor boxer in Philadelphia.

"Baltimore is a great working-class city, too," the actor says. "It has it all — gritty, nice, suburbs. I come from a working-class family. My mother was a teacher; my dad was a handyman who refinished kitchens and appliances. I try to take all of this into the character of Rocky. I'm not down-and-out and poor as he was, but I feel I know something about him."

When Karl met co-star Seibert, he discovered they had a lot in common. For one thing, right after they were hired for "Rocky," they each got a good-luck call from the same woman in Columbia — Toby Orenstein, founder of Toby's Dinner Theatre.

"In the big wide would of theater, to find two actors who played here who have both ended up as leads on Broadway is pretty exciting," Orenstein says. "They're both humble and hardworking. I wish them real success. They deserve it."

Seibert, who was born in Olney and raised in rural Glenelg ("We lived on 7 acres and I used to mow all of that on a tractor"), made her Toby's debut as the Mistress in "Evita" when she was 16

"I had been an ice cream scooper and a hostess there first," the actress says, adding with a laugh: "I really worked my way up."

Orenstein had no doubt about Seibert's potential.

"I knew she was something special," Orenstein says. "She was going to be a star."