"Look at where we live!" Billie Joe Armstrong, the frontman of Oakland pop-punk veteran Green Day, exclaimed Tuesday night at the Forum, where he spent considerable time extolling the virtues of life in California after spending two months on the road. The show capped the band's North American tour in support of its latest album, "21st Century Breakdown," the follow-up to its Grammy winning epic "American Idiot." "We've just gotta get rid of Arnold Schwarzenegger," Armstrong continued, riling the already enthusiastic crowd. "We're bankrupt! But tonight we're not bankrupt of hope, or of belief." At the Forum, business in belief was booming. Over three action-packed hours, Green Day proved that the arena-rock concert -- usually a venue for chest-beating bravado and shallow bombast -- can be a meaningful experience, an opportunity for a band with something to say, to say it.

Not that Armstrong and his bandmates are uninterested in chest-beating bravado and shallow bombast: During "Brain Stew," the singer soaked fans near the stage with an oversized water gun, then traded up to an air-powered T-shirt launcher, sending free Green Day merchandise rocketing into the cheap seats. (He did this while wearing a pair of felt bunny ears offered up by an audience member.)



And though Armstrong announced early on that he viewed the show as an in-the-moment repudiation of our increasing addiction to television, computers and cellphones, the production featured no shortage of high-tech stagecraft, including a video-screen backdrop and columns of color-coordinated fire.



Yet the soul of Tuesday's concert was the band's message of secular humanism in an age of "static and contraband" as Armstrong sang in "Song of the Century."



Green Day's transformation into a thoughtful political outfit has perhaps come as a surprise to the band's old-school fans, who remember when Armstrong was better known for his depictions of the young and the listless. But George W. Bush's presidency radicalized Armstrong, and since then he's used Green Day's music to poke at power and to sketch out a democratic ideal he refers to in the new album's "Know Your Enemy" as a "choir infantry."



Democracy took real-life form several times Tuesday, when Armstrong pulled fans onstage to sing "Longview" and play guitar on "Jesus of Suburbia." Punk groups often talk about breaking down the barrier between performer and spectator; Green Day actually did it.



Punk groups don't often talk about wanting to sound like the E Street Band, but Green Day did that too, sweetening its attack with the help of three auxiliary musicians, who added keyboards, saxophone and thick vocal harmonies to music that somehow retained a breakneck propulsion.



Near the end of the show -- which Glasgow's Franz Ferdinand opened with a tidy 35-minute set of taut disco-rock -- the band paid homage to a series of other influences in a rapid-fire medley containing snippets of songs by the Doors, the Isley Brothers and the Rolling Stones. The bit served to illustrate Green Day's admirably open-armed approach, but it also underscored the group's new belief in public service: Here was one of the world's most popular rock bands acting as a humble jukebox for 18,000 or so screaming Southern Californians.

--Mikael Wood

Photo credit: Getty Images