Just in case anyone hadn’t realized that Foster the People is a keyboard-oriented outfit, five synthesizers and electronic pianos dominated the band’s setup Monday night at the 9:30 Club. That was more than the quintet’s members could play at one time, since drummer Mark Pontius never left his kit, which was placed off to one side. But the abundant keyboards (and a spare drum) allowed multi-instrumentalist Mark Foster to ricochet about the stage, pounding a beat here or tinkling a riff there. Three of the other players also regularly switched instruments and locations, adding dynamism to a show that was effectively all about a single song.

That song is “Pumped Up Kicks,” a bouncy hit that assumes the viewpoint of a guy who’s apparently about to perpetrate a mass murder. “You better run, better run, outrun my gun,” the audience sang cheerily when the tune finally arrived at the end of the band’s earlier set (the first of two sold-out Monday shows). Turning the homicidal singalong into even more of a party, Foster and the people (the group’s original name) interjected a dance-remix passage, sampling and looping the chorus into a clipped, house-style groove. And the members of Reptar, the somewhat trippy opening act, rushed onto the stage, banging hand-held percussion instruments. This spun the well-planned set back to its opening number, “Houdini,” which began with most of the musicians banging or clanging on something.

Foster may not be a profound social critic, but he’s a clever arranger and an eclectic composer. His band’s style is basically early-’80s dance-rock, closer to Duran Duran than New Order. But he has a piano-man side that occasionally suggests Billy Joel, and his penchant for falsetto singing (and the phrase “oo-oo-ooh”) recalls such ’70s bubble gum-soul acts as the Stylistics. A former jingle writer, Foster knows how to deploy a hook but makes his songs sound edgier than they are with disco beats and dub-inspired moments in which most of the instruments temporarily depart.

The band’s minimalist tendencies were underscored by the prison-break staging, which relied on stark white strobes and spotlights, only occasionally accented by other hues. During a few songs, notably those where the frontman played guitar, the effect was sufficiently martial to suggest that Foster the People might actually be packing heat. But then it was time for another “oo-oo-ooh.”

Jenkins is a freelance writer.