Imagine Frankie Valli stepping in on vocals for Jersey Boys. Or Ringo Starr manning the drum kit for the Beatles tribute Rain. Such is the electrifying effect of the presence of Green Day frontman Billie Joe Armstrong as the drug dealing St. Jimmy in American Idiot, the Broadway musical inspired by the best-selling pop-punk band’s Grammy winning 2004 concept album.

Armstrong has been involved with the show from the start, developing it and co-writing the book with director Michael Mayer. He also stepped into the show for a brief one-week run last September, which inevitably resulted in a massive hike in ticket sales.

Now, in an effort to boost box-office during the traditionally slow winter months, he’s in the midst of a sporadic 50 performance run. He played the role through January 30 and will return for a two-week engagement, running February 10-27.

His guest turn brings even more energy to a show that already suffers from no shortage of it. Despite his rock stardom and hugely charismatic stage presence, he melds seamlessly into an ensemble whose performances have only gotten stronger since the show opened last April.

The 95-minute musical incorporates all of the music from the titular album, as well as selections from the band’s 21st Century Breakdown and several other songs. The storyline concerns three disaffected suburban youth and the disparate paths on which they embark.

Johnny (John Gallagher, Jr.) heads to the big city, where he falls in love with Whatsername (Rebecca Naomi Jones) even while falling prey to drug addition at the hands of St. Jimmy. Tunny (Stark Sands) enlists in the army and is sent to Iraq, where he is gravely wounded. And Will (Michael Esper) finds himself stuck in suburbia, struggling to support his wife (Jeanna de Waal) and baby.

While the thinly drawn story and characters never become truly involving, Mayer’s propulsive staging smashingly overcomes the material’s flaws. Tom Kitt’s arrangements effectively theatricalize the hard-rocking and frequently melodic songs while diluting none of their original power. And Stephen Hoggett’s relentlessly energetic choreography is superbly performed by the youthful ensemble.

Far from being an example of stunt casting, Armstrong delivers a knockout turn, providing a devilishly antic spin to the character that is consistently mesmerizing. And, needless to say, he’s in utter command of the music. When he performs the hit song “Time of Your Life” at the encore, it’s sheer nirvana for the blissed-out Green Day fans.

Rock fans take note: Melissa Etheridge will be stepping into the role from Feb. 1-6. Is this the start of a series of guest stars ala the revival of Chicago?

St. James Theatre, 246 W. 44th St. 212-239-6200. www.telecharge.com.