It was an all-ages crowd at the 9:30 club on Wednesday night, which made good sense given that the main attraction -- the spunky prodigy Ben Kweller -- is barely of drinking age himself. At one point Kweller, who looked stylishly scrawny in bell-bottom jeans and a tight T-shirt, sympathized with the under-agers who couldn't buy a drink. "I just turned 21 back in June," he explained.

The mop-topped Kweller may be a kid, but he's no cheesy teen idol. An indie rock wunderkind since forming the acclaimed punk band Radish at the freakish age of 12, he's a gifted songwriter and guitarist who writes playful, lively tunes that bounce like a Superball.

Kweller's 9:30 set consisted mainly of songs from his infectious 2002 solo album, "Sha Sha" -- a collection of Beatles-influenced pop fueled by blaring guitars and Ben Folds Five-ish piano -- including the punky "Wasted and Ready," "Walk on Me" and the pretty ballad "Family Tree." Throughout, Kweller burned off spare energy through spastic kicks and leaps around the stage, an endearing reminder of his tender age. (As were his whimsical lyrics, such as "Don't bother me when I'm watching 'Planet of the Apes' on TV" and "Sex reminds her of eating spaghetti / I am wasted but I'm ready.") Kweller also sat behind an electric piano for several tunes, leading his three-piece band through songs such as the set-capping "Falling," which culminated with some wonderfully giddy key-banging.

The slick production of "Sha Sha" gave it a radiant warmth that was at times lacking onstage; Kweller and his band mates often sounded muddy and flat by comparison. But the good news for Kweller is that he's got plenty of time to fine-tune his immensely promising act.

-- Michael Crowley

Kweller, 21, played songs mainly from his infectious CD "Sha Sha."