Searching for his way into the new musical "Backbeat," which examines the Beatles' early days (and nights) in Hamburg, Germany, David Leveaux asked himself what he called "the Jerome Robbins question."

It's a tactic he picked up in 2004 while overseeing a Broadway revival of "Fiddler on the Roof." That show's book writer, Joseph Stein, was recounting his experience on Robbins' original 1964 production and told Leveaux that one day the director asked, 'OK, so what is this musical about? I want one word,'" Leveaux said.

Stein made a list: "parents," "daughters" and, way down at No. 15, "tradition." "Robbins got to that and said, 'That's it - now every scene has to be about tradition,'" Leveaux said. "And the result was this legendary musical."

For "Backbeat," Leveaux might've used "love" or "mop top." Maybe even "ob-la-di." He picked "courage."

"Think about it: You come out of a postwar working-class environment in Liverpool," the English director said, speaking backstage at the Ahmanson Theatre, where "Backbeat" began a month-long run Wednesday night after earlier engagements in Glasgow, London and Toronto. "You go to this very strange place in Hamburg, the Reeperbahn," or red-light district. "It's a threatening place - a dangerous place, in many ways. And you're playing rock 'n' roll, which itself is causing all manner of aggression.

"But then you discover, if you're John Lennon, that this man who you love deeply, your best friend, is now falling in love with someone else and is going to leave your band." Leveaux shook his head at the thought. "What are you going to do about that?"

If this part of the Beatles' story doesn't sound familiar, that's more or less the point of "Backbeat," said Iain Softley, who co-wrote the show with Stephen Jeffreys. Based on Softley's 1994 film of the same title, "Backbeat" takes up the gritty pre-history of the band that would go on to change pop music. And it reflects a shift in musical theater - one demonstrated recently by "Fela!" and "Once" - away from the conventional actors-accompanied-by-orchestra setup toward a more integrated, concert-like approach.

Beneath those formal innovations, though, "Backbeat's" heart is the love triangle that connected Lennon (played by Andrew Knott), the Beatles' original bassist, Stuart Sutcliffe (Nick Blood), and Astrid Kirchherr (Leanne Best), the German photographer with whom Sutcliffe was involved until his death in 1962.

"Stuart had to choose between his best friend and his girlfriend and between touring the world and staying in Germany," said Softley. "That dilemma is what made me feel the story had dramatic potential."

There was also the musical challenge the Beatles faced as the band (with founding drummer Pete Best) honed its chops playing covers of American R&B tunes in rowdy Hamburg clubs. (The show's score features "Long Tall Sally" and "Twist and Shout," among other classics, as well as a few early Lennon-McCartney songs.)

Leveaux said his goal with the show is to "unravel the reflexive expectations of fame," to embody the spirit of George Harrison's assertion that the Beatles didn't want to be famous - they wanted to be successful. "It's a pretty interesting statement," the director pointed out, before adding with a laugh, "I'll probably regret saying this, but in that way I think 'Backbeat' is almost the anti-'American Idol.'"

In his movie Softley got at that edgy intensity in part by assembling an alternative-rock dream team, including Nirvana's Dave Grohl and Thurston Moore of Sonic Youth, to perform the film's music. (Its out-of-print soundtrack remains a rough-cut gem.) For the theatrical version of "Backbeat" - which England's Guardian newspaper called "intelligent, multilayered and often touching" - Leveaux does it with a nearly club-like staging built around the band's gear.

"Guitars are there and the silhouette of a drum kit is there, even when we find Stuart on the beach," he said. "You never want to take that away, because if you do, then suddenly you think, 'OK, we're in a play now and we'll get back to the rock 'n' roll later.'"

The production also enlisted Paul Stacey, who's toured with Oasis and the Black Crowes, as music supervisor to get the actors to a level of credible musicianship, since they play all of the Beatles' songs.

"One of the reasons you go to the theater is to feel more alive," he said. "It's a transmission of energy. The energy is how you convey feeling and emotion, and that's not descriptive. Often the most powerful forms of theater are not forms that describe the experience - they are the experience."