Sonically, the two genres are worlds apart. Broadway's best music is sophisticated in construction and execution, and is, generally, all about melody. Punk, on the other hand, is best served on a minimalist instrumental platter, and can be virulently unmelodic.
Which makes "American Idiot" - which opened in 2010 and makes its Philadelphia debut Tuesday - one of the most surprising successes in recent Broadway memory, and perhaps one of the most unexpected hits in all of musical theater history.
"American Idiot" is based on the 2004 album of the same name by modern-punk titans Green Day. Set in the middle of the last decade, it is an unstinting, gimlet-eyed look at the rudderless, hedonistic lives of a certain strata of suburban teens of the era.
According to the show's musical supervisor, those involved in its creation were, from the outset, determined to remain true to Green Day's musical blueprint, and were adamant about not gussying up the source material beyond what was absolutely necessary.
"In the original conversations and the genesis of the idea, it was really important to the creators to stay really true to the punk-rock aspect of it. And I know that was important to Green Day as well that [the creative team] didn't try to 'musical theaterize' the piece," offered Jared Stein, who has been with the show since its inception, during a recent phone call.
"What [orchestrator-arranger] Tom Kitt did, in his brilliance, is he just sort of amped up what was already there and decide to add strings to it and do some more complicated vocal arrangements.
"I think that's where he kind of theatricalized it a bit, with those elements, without trying to change the genre or style of what the music already was."
Stein suggested the most difficult part of the adaptation process was finding the middle ground between the amped-up volume punk rock feeds on and the aural demands of traditional musical theater.
"The biggest part of the balance," he said, "is in the sound - that we stay true to the punk-rock thing, and it's loud and it's rock - but that we are able to hear those melodies and lyrics so we can really focus on telling the story."
Before being asked to participate in "American Idiot," Stein worked on such hits as "The Who's Tommy," "Spring Awakening" and "Rent" (which he claims as his personal favorite). As such, he said, he bought in immediately when he was invited to work on "Idiot."
"To take an album and put it onstage makes perfect sense to me," he said. "All these super-epic concept albums are just screaming to be put onstage and have some theatricality put behind them.
"So, when I heard about it, it was like, 'Oh, my God, that's gonna be amazing!' "
That opinion has been shared not only by audiences who have made "American Idiot" a commercial juggernaut, but by critics, too, most notably Charles Isherwood of the New York Times, who described the show as "thrillingly gorgeous and raucously wrought."
As for the public, Stein noted his musical's constituency is not limited to Green Day fans.
"I actually find audiences to be quite diverse," he said. "We see the typical Green Day fan, but also a bit of an older crowd coming to take a risk on it,
"We also found an even-younger crowd [on Broadway]. I'm talking like 7-year-olds, 10-year-olds, who would be sitting there with their parents, who grew up on the early Green Day stuff and are willing to expose their kids to this. And the youngsters] would be sitting there mouthing every word.
"It's nice to see this is continuing on and they're creating a younger fan base as well."
Merriam Theater, 7:30 p.m., Tuesday through Thursday, 8 p.m. Feb. 15, 2 and 8 p.m. Feb. 16, 1 and 6:30 p.m. Feb. 17, $100-$20, 215-893-1999, kimmelcenter.org.