Preview: The Bays With Richard Barbieri & Matt White, Queen Elizabeth Hall, London

The Bays refuse to release albums or rehearse, and insist on complete improvisation when playing live - common in jazz, but not in rock and dance music. But this London quartet spontaneously transform the matter of techno, house, drum'n'bass and breakbeat into malleable, hypnotic epics. Remarkably, they don't even use sequencers.

The Bays refuse to release albums or rehearse, and insist on complete improvisation when playing live - common in jazz, but not in rock and dance music. But this London quartet spontaneously transform the matter of techno, house, drum'n'bass and breakbeat into malleable, hypnotic epics. Remarkably, they don't even use sequencers.

It's not so much the documentation of their work they oppose, but rather its potential commodification. The foursome are quite happy to record every performance, making them available for free downloads on their website.

The roots of The Bays can be traced to the turn of the millennium, when the drummer Andy Gangadeen acted as host for a revolving collective. "The concept was the same, doing music that was improvised, but not jazz. It came out of seeing The Roots playing. They just had Rhodes [electric piano], bass and drums. A minimal, powerful sound."

"The most interesting element, as a musician, is always the first time you do something," says the bassist Chris Taylor.

"It's dance music," says the keyboardist and electronics manipulator Simon Richmond, "informed by the same kind of thing that DJ breaks music is created for: the groove and the collective rhythm rather than a background for someone to noodle over the top. What we're interested in is spontaneously recreating, as a performance, the kind of thing that people would normally do with drum machines and sequencers. There's nothing unnecessary in there."

"It's almost to our disadvantage that we are so precise with our changes, because it looks like it's worked out when it isn't," says Taylor. "A lot of the time, people don't believe that it's improvised."

"There is a degree of telepathy now," agrees Richmond. "What it isn't," declares Taylor, "is a backing with a solo voice. It's all solo voice."

Tonight (0870 380 0400); then touring ( www.thebays.com)