Fall Out Boy stay young together at the Electric Factory

Depending on how you read it, the title of Fall Out Boy's Save Rock and Roll can be seen as a call to arms or a comic-book boast: Are they asking us to save rock, or letting us know they've got the situation in hand?

At a sold-out Electric Factory on Thursday night, they were cheerleaders and saviors both, rallying an adoring crowd and urging them to find their own way.

Part of the motivation for "Fall Out Boy 2.0," as bassist Pete Wentz dubbed the band's return from a four-year hiatus, was inspiring younger generations to pick up the torch. As Green Day's playfully sneering pop led him to punk forbears like the Misfits and the Refused, so, Wentz explained, Save Rock and Roll might lead someone in the audience to form "the next Misfits or the next Refused . . . or the next Fall Out Boy."

But, while Wentz talked like a three-chord traditionalist - and looked the part, in his leather bondage boots - Fall Out Boy's music has taken them far from whatever punk roots they once had, into territory more distinctively their own. Their records mix singer Patrick Stump's soulful wail and self-consciously overwrought lyrics with the deluxe production aesthetics of hip-hop. On stage, it was mostly two guitars, bass and drums, although a prerecorded track supplied the requisite gospel choir "fi-yaaahh" for "My Songs Know What You Did in the Dark." (That, incidentally, is a fairly concise name for a band whose song titles rival Fiona Apple's albums' in length.)

The band's boundless confidence can be exhilarating, but it has its pitfalls. "Young Volcanoes" came off as an anthem in search of a cause, all hollow bombast and empty gesture, and Save Rock and Roll's title track was a ponderous slog weighed down by Stump's midtempo piano. Surely an ode to rock ought to actually, like, rock.

If not by rock-and-roll, exactly, the day was saved by songs like "Thks fr th mmrs," a hurtling text-message kiss-off to an ex-lover, and "The Phoenix," which began with Stump urging us to "Put on your war paint."

The crowd, who seemed to know every word to songs old and new, needed no reminder to gird themselves for battle.

"We could stay young together," Stump sang in "Alone Together," a hymn to finding community through song. "Scream it from the top of your lungs." And they did.