As the pianist in Mike Gibbs's big band, Hans Koller is well used to wrestling with challenging musical charts. But this evening, his compositions are so bewilderingly complex that they are starting to flummox even him. "I can't remember the form of this one, or how it begins, let alone how it ends," he confesses, and the audience laugh understandingly. Koller asks for 20 seconds to collect himself, then announces he is back on planet earth and counts in the band.

It isn't hard to see why Koller's brain is starting to hurt. The music he has written for his 12-piece group is an astonishing tapestry of angular riffs, ever shifting accents and skittish modulations, made all the more disorientating by a series of outlandish solos. Evan Parker contributes some of the maddest, tearing up and down his soprano saxophone while managing to sound like a brass section that is being attacked by spanners. The cumulative effect is often thrilling, and it pins Koller's audience to the wall.

Tunes with such minimalist titles as Herb, Mystery and Libertine fly and glide above a rattling rhythm section consisting of a drummer and two double basses. Fitful eddies of woodwind vie with jabbering saxophones, a violin wails, trombones strike up with snappy two-note shouts and Koller's piano circles endlessly as if trying to find a key to feel comfortable in. None of it should work, but nearly all of it does.

There are slower, restful numbers, including the ethereal, Latin-flavoured Farewell and a haunting reverie called Airy in which brass notes gleam like tubular bells above a gently pulsing double bass ostinato. But the overall impression is one of zestful, left-field hyperactivity. Koller's music gives more than the occasional nod to Gil Evans, Carla Bley and the cathartic pandemonium of Loose Tubes, but he has managed to put his own dizzying spin on them all.

·At the Royal Festival Hall, London SE1, on May 25. Box office: 020-7960 4242.