A cacophony of noise comes from somewhere in the audience. Walking out from behind tables, six-piece Guillemots slowly converge on the stage, creating a joyful free-jazz din in the process.
Fronted by Birmingham-born songwriter Fyfe Antony Dangerfield Hutchins, Guillemots have been attracting praise of late, counting such presenters as Steve Lamacq, Zane Lowe and Jo Whiley among their army of admirers.
It's not an opinion shared by one critic, who called the jazz-influenced band a "stupefyingly bad mix of Keane and Kenny G". Judging by this engaging performance, that statement seems more than a little misguided.
Guillemots' anthemic songs are most closely reminiscent of Radiohead, if Thom Yorke listened to Elton John and Billy Joel rather than Aphex Twin. With a subtle combination of keyboards, guitar, double bass and saxophones, they confidently bridge the gap between a keen sense of melody and sonic adventure, with experimentation often coming gift-wrapped within deliriously rousing tunes.
But it's difficult to pigeonhole Guillemots because of their willingness to defy expectations. Musical styles are flirted with, and Hutchins even performs one track virtually unaccompanied, save for a handilyplaced mini keyboard.
Leaving instruments at the edge of the stage, urging audience members to come forward to play them, they bear the hallmark of a truly uncompromising band.
Guillemots are a hugely exciting act, combining jazz and conventional rock songs more satisfyingly than anybody since Morphine - they have the songs to match their ambition, but rest assured they'll do it on their own terms.