Stereolab is not exactly a great band, but it is a great idea: Velvet Underground and Krautrock drone meet Brazilian-samba saunter and Gallic-pop bounce, with a few Steve Reich phase patterns adding a minimalist groove. On recent albums like the new "Cobra and Phases Group Play Voltage in the Milky Night," the British sextet has deemphasized the noisier parts of this formula, with results that are sometimes bland. But composer-guitarist Tim Gane's rowdier instincts reassert themselves onstage, as the band's Wednesday set at the 9:30 club demonstrated.

The concert emphasized such recent songs as "Infinity Girl," but the sound often drew on the band's looser, rougher, early approach. The more melodic passages emphasized keyboards--played throughout the show by Morgane Lhote and occasionally by most of the other musicians--and Laetitia Sadier and Mary Hansen's almost easy-listening vocals. Yet the songs frequently veered into more cacophonous, guitar-dominated territory, and at various times both Sadier and Hansen joined Gane in strumming the guitar chords that threatened to lead (but never quite did) into the Velvets' "Sister Ray." There's not much variation within Stereolab's droning and bouncy styles, but the collision of the two still shoots off sparks.