There's a capacity crowd at the ICA, but Three Machines seem to be coping with the excitement. For most of the night brothers Brandon and Benjamin Curtis and drummer Josh Garza are silhouettes shrouded in a cloud of dry ice. They face inwards in a triangle, and the feeling is that we're spying on a band jamming: at no point do they attempt to engage the audience.

On record, their rolling soundscapes, reminiscent of mid-period Pink Floyd, also betray a love of Krautrock's motorik impulse. Here at the ICA there's little of Krautrock's subtlety, discipline or playfulness, despite a cover of Monza (Rauf und Runter) by obscure post-Neu! band Harmonia. Garza isn't the most delicate of drummers: though sometimes his thuddingly repetitive patterns bash through the boredom threshold to attain the insistence of a heartbeat, after an evening of crash, bang, wallop you're desperate to hear the odd jazz fill.

Much of the time, the impression is of musicians still exploring their synergy, perhaps a little too drunk on their ability to make their instruments go whoosh. There's none of fellow Texans Lift to Experience's mystic vision here, nor Explosions in the Sky's ability to extrapolate a world of feeling from only a few chiming notes.

That said, there is much to praise. First Wave Intact erupts unexpectedly into a gloriously melodramatic, falsetto chorus reminiscent of no one more than Cheap Trick. Sad and Lonely is a brutishly wry kiss-off to an ex-lover, tongue unexpectedly in cheek. Secret Machines are sufficiently out of step with trends in American alternative rock to be worth watching. A few wrong moves, however, and they'll be the alt.rock Spinal Tap.