Gavin Bryars was always the joker in the pack of English Experimentalis ts. But his latest piece is a real gamble. Can he and Spanish artist Juan Munoz really pull off the trick of playing cards on the radio - and score a full house?
"Good Evening. Welcome once again to A Man in a Room, Gambling. We will start today's programme, if we may, with an apology - we have lost today's programme somewhere... but seeing as we promised it earlier..."

For Gavin Bryars - erstwhile founder of the Portsmouth Sinfonia (an orchestra made up of un-musical members) and 1993 Mercury Music Prize nominee (for Jesus' Blood Never Failed Me Yet, a loop-tape of a tramp rambling) - it's a typically tricksy beginning to his latest collaborative venture, a series of pieces devised with Spanish sculptor Juan Munoz, offering tips for cardsharps. Against Bryars' lush low strings, Munoz delivers a series of heavily accented deck-fixing masterclasses.

"Some people with a high moral sense use the word tricks to describe these subtle techniques," intones Munoz to the dreamily mellifluous orchestration. "But we prefer to call them artifices."

A Man in a Room, Gambling, which is both premiered in London tomorrow and released this week on Philip Glass's Point Music label, was seemingly inspired by a genuine turn-of-the-century gamblers' guide, The Expert at the Card Table, written by a shadowy Canadian trickster by the name of SW Erdnase.

In the hope of acquiring some new poker-playing wisdom, and a speck of insight into the world of SW Erdnase, I slip a pack of playing cards into my handbag and set off to visit Gavin Bryars.

My cards are particularly fine ones, decorated with a determined-looking Mountie: just right for investigating a Canadian criminal, but Erdnase slips through my fingers.

"I don't know anything about Erdnase," admits Bryars drily. "Munoz came up with the texts."

A game of poker, then? No, Bryars doesn't enjoy cards.

Good Morning. Welcome once again to A Man in a Room, Composing. We will start today's interview, if we may, with an apology - we have lost today's interview somewhere - but seeing as we promised it earlier...

Munoz and Bryars, it would seem, are both dealing from the bottom of the pack. A Man in a Room, Gambling (which was commissioned by Artangel, the people who brought you Rachel Whiteread's House) is not really about gambling.

Each of the pieces is exactly five minutes long and presented as if it were some weird radio broadcast. "We're playing with perceptions," explains Bryars. "The idea of a sculptor making a radio piece is a kind of curious one, especially as he is working with a non-visual medium to create visual illusions, making cards disappear."

Musician and artist work together to baffle the listener. As a listener, you try to focus on Munoz's instructions - attempting to visualise the trick being described - but a particularly melodic phrase in the music will suddenly distract your attention and you immediately lose track. "You've been deceived - just like the sleight of hand the trickster might use," says Bryars.

From time to time, a confused Japanese voice tries to catch up with the action, repeating isolated phrases into an off-stage mike to further highlight the bafflement and dislocation. Meanwhile, disquiet grows as the slightly sinister instructor whispers advice about "cutting", "disposal" and "laying face downwards". Breezy harmonies are punctuated with muffled bells, drifting echoingly off to eerie malevolence. The piece is austerely presented without any visual effects.

"It should be as if you were witnessing a radio performance," says Bryars. "It was designed to be done rather like the Shipping Forecast, so that you'd stumble across it by accident while waiting for something else." In Canada, where A Man in a Room, Gambling has already slipped into radio schedules, these peculiar snatches of sound have achieved something of a cult following, with Michael Ondaatje a particular fan. In Britain the BBC is dragging its heels, unsure whether to slot the pieces into Radio 3 or Radio 4.

"The aim of the piece, as with the Shipping Forecast, is to give the listener a hazy impression of a dramatic activity taking place in areas whose precise locations are only vaguely sensed," says Bryars. "Five minutes of radio can generate such an emotionally powerful imaginary space."

Bryars, whose eldest brother was a sea captain, grew up in Goole, East Yorkshire, England's largest inland port; and both the sea and the radio have been a constant presence throughout his life. "I was brought up in the radio era," says Bryars, who was born in 1943. "Certain rituals governed listening to shows like Ken Sykora's Guitar Club, The Goon Show and Jazz Record Requests, sitting down with chips and pickled onions on a Sunday lunchtime; or tuning in on a Saturday, after playing football in the morning...

"My eldest sister's husband set up a radio extension in the kitchen, which was unheard of in those days, and we were so proud of it," he recalls, padding round his own kitchen now, ladling Branston pickle on to a cheese sandwich. Radio rituals still prevail, he explains, getting up every morning and switching on a dozen different radios in turn as he moves through the house, all of them tuned to Radio 3.

A new radio has recently brought strife to the Bryars household, however. "I've got a wonderful cap I bought up at Old Trafford," he explains, "which comes fitted with a tiny radio pre-tuned to Test Match Special."

"You know you're not allowed to wear that, Dad," tut his teenage daughters Ziella and Orlanda firmly. Both girls play the cello in their father's ensemble and will be taking part in this week's performances of A Man in a Room, but at the moment they're standing at the sink, scrubbing blood from their hands, trying their best to expunge the evidence of the slasher movie they're filming with friends amid the Montbretia in the back garden.

"Oh, well, they are my fashion gurus," their father concedes.

I suppose even the coolest dad, with a zero haircut, and a line of pop stars queuing up to work with him, never seems quite so cool to his own daughters. This afternoon's collaborative exercise (after he's bought the family dog's birthday present), is to run up some arrangements for former 10,000 Maniacs singer Natalie Merchant. Bryars works prolifically and exceedingly quickly, and he'll need to, with a diary of commissions stretching into 2002.

In June 1998, his much-postponed opera Dr Ox's Experiment, a collaboration with Blake Morrison based, like much of Bryars' work, on a Jules Verne story, opens at the London Coliseum. Next to join his list of collaborators (like director Robert Wilson and Bruce McLean) are film director Atom Egoyan and dancer Merce Cunningham.

Probably as a result of the 17 years spent as a jazzman, Bryars would always rather collaborate with others. "That's why I don't just compose, but have my own ensemble, which demonstrates music is a social act," he says. "It is not something one does hermetically in a room, where the composer sends it out and someone else does it." Bryars does not, in fact, believe in a man in a room, composing.

`A Man in a Room, Gambling': 8pm tomorrow to Sat, Studio 1, BBC Maida Vale, Delaware Rd, London W9 (booking: 0171-960 4242) and released on CD this week by Point Music/Philips Classics (CD 456 514-2)