The Black Rider (DAVID COULTER - musical director) | Storm in a pawnshop

The Guardian | John L. Walters

With its drunken piano, pocket trumpet and musical saw, The Black Rider is obscure-instrument heaven.

The songs of Tom Waits are inherently visual - not just in their words and themes, but in the way they sound. Just as film footage of a lake, or a country house acquires mystery and glamour when underscored by a chugging Nymanesque riff, images of cheap house-fronts and dusty streets take on extra gravitas when accompanied by Waits's ragged tracks. Check out Jim Jarmusch's Down by Law and Night on Earth, or Francis Ford Coppola's fabulous One from the Heart.

The band currently playing in the Barbican Theatre pit have the challenge of re-creating Waits's distinctive instrumental timbres every night. "There are certain things you need to play his music," says associate musical director David Coulter, chatting backstage. "There's upright bass, of course, and pump organ and drunken piano; lots of things that are slightly out of tune with each other, or 'sour', to use Waits's own word."

Coulter, a musical-saw virtuoso who plays another 20 instruments, is the man who put together the band for The Black Rider, the show by Tom Waits, Robert Wilson and William S Burroughs opening at the Barbican tonight after four nights of previews.

Given the palette of sounds needed for Waits's idiosyncrasies, the band has to have a wide range of sounds, styles and skills at their fingertips. Led by musical director Bent Clausen, who plays drums, keyboards and marimba, the eight-piece group has the tough job of capturing the spirit of Waits's messy, freewheeling music while sticking to all the dramatic cues in this demanding, visually rich production. Clausen is a Waits veteran who played on the albums Alice and Blood Money, and worked with Waits and Wilson on Woyzeck.

So the musicians' pit looks like a downtown pawnshop, packed with arcane and/or beautiful instruments: bass clarinet, toy piano, pocket trumpet, accordion, Stroh violin, mandolin, ondes martenot, glass harmonica, cristal Baschet.

The last three are specialities of Thomas Bloch, whose CV includes Messiaen's Turangalila and sessions with Radiohead. Kate St John ( Dream Academy) Caroline Hall, Jack Pinter and Terry Edwards (Scapegoats, Lydia Lunch) play on a huge variety of wind instruments. The ensemble is underpinned by bassist Rory McFarlane, looming out of the pit's seething activity like a mariner clutching the mast of a boat.

If you've heard The Black Rider ( Island, £8.99), you'll have some idea what to expect. Except that Waits's studio recordings are more like miniatures - lovingly made "bigatures" - with Waits taking all the parts himself. The Barbican band has to fill the theatre with a Waits-like sound and accompany a dozen diverse performers, singing, speaking, raging, howling or mute.

This is neither West End musical nor hardcore music theatre. Rather than developing motifs in a compositional way, Waits transforms his material through extremities of sounds. This is hard to notate. In the words of Coulter (who, like Waits himself, doesn't really read music), it's more "organic".

The musical language for the show is established early, with an introductory circus-like theme that jumps in every other bar, as if transcribed from a scratched record. For another scene the ensemble boils menacingly, with little bubbles of free improv escaping from the sonic soup, while a hallucinatory three-note flugel phrase floats overhead. Another potentially static segment derives its richness from the harmonic complexity of Coulter's didgeridoo.

Out in the hall, the mix was superb, its unholy instrumental alliance sounding entirely natural. Many featured instruments - Swanee whistle, musical saw, trombone - can stray far from the diatonic path. The ensemble sections have the requisite sourness. Yet it's a disciplined, professional sound, a swanky showbiz version of the microtonal explorations of Frank Denyer or Harry Partch.

And whether the band is required to rock or swing, play sentimental ballads or demented burlesque, they never step out of character - the huffing, puffing fantasy band created from Waits's rugged templates.