MUSIC / Graphic guide to music-making: Barry Guy plays everything from baroque to hot bass, but he also improvises a pretty mean concerto. Nick Kimberley reports

OUR retrospective age requires musicians familiar with huge vistas of musical history, but few musicians cover quite as broad a span as double-bassist Barry Guy. For many years he has been a period instrument specialist, playing Monteverdi with John Eliot Gardiner, Mozart with Christopher Hogwood and Beethoven with Roger Norrington. He is also one of the few musicians technically and imaginatively equipped to deal with the toughest contemporary scores, by Xenakis or whomever. Then again he is a skilled improviser, playing solo or in varied aggregations in those few venues that provide a haven for the improviser's art.

And there's more, for Guy also composes - his Flagwalk was performed earlier this week by the Orchestra of St John's Smith Square (see review, p 33); and tomorrow at London's Institute of Contemporary Arts he directs the London premiere of his Bird Gong Game. A formidable array of musical activities, which would drain most musicians. Guy stays alert by only involving himself in music he cares passionately about.

Experience has shown how important that is: 'Back in the 1970s I had some bad experiences with symphony orchestras which did not endear me to that kind of life. The smaller the group, and the more intense the music-making, the more important it is.' Shortly after this came the pivotal moment for those period instrument orchestras - like the Academy of Ancient Music, the English Baroque Soloists, the London Classical Players - which so transformed music-making in this country.

Guy found it exciting to play with such groups: 'New ideas were flowering, the music had a completely different feel to it. It was mind-boggling, a bit like being a detective: buying old instruments, finding out how to get the best out of them, trying different bows, different ways of articulation. I was as excited about that as about working with contemporary music.'

Sadly the exhilaration has not survived: 'It got taken over by record companies. More and more I was going into the studio to record bits of music that were put together in the editing suite. It wasn't honest any more, it was like being an animal in a zoo - you're fed well, looked after, you have nothing to worry about. But my friends were having a great time out in the jungle, even if it was hard. I had to open the cage.'

Now Guy fights it out in the jungle. As a composer, he says, 'I write mostly for friends, whether it's a chamber ensemble or a soloist. It's a microscopic process of looking inside music for the possibilities for individuals. I wrote a solo oboe piece for Robin Cantor, who wanted something different from the playing of his teacher, Heinz Holliger. In a series of meetings and discussions he steered me away from any Holligerisms. It's a bit like making a suit: I dressed it around him. That's the important aspect of composition for me.

'My greatest joy is playing improvised music. It's being created there and then, but with a background of disciplines and techniques that are second to none. The door is always open for things to happen, and the best improvisation often has better credentials for music-making than composition.'

This weekend Guy pits his wits against - and collaborates with - improvisers and score-led musicians when he directs his graphic piece, Bird Gong Game, written for the ensemble Gemini (playing from a score) and an improviser (with no score). On this occasion, there will be two performances, each with a different improvising soloist: saxophonist Evan Parker, and vocalist Maggie Nicols.

A double performance is viable because, although the score exists on the page, its order is open-ended, determined by Guy according to how soloist and ensemble interact. Each section of the score is governed by a symbol on a series of cards that Guy holds up, in an order occasioned by the moment, so as to direct the ensemble, or individual members - but not the soloist - to particular parts of the score. Graphic notation at several points necessitates on-the-spot invention, allowing potentially endless interpretation (although in practice Guy finds that 15 to 20 minutes is the optimum duration).

Guy explains the genesis of the score: 'It's a private piece. Last year the painter Alan Davie had a big retrospective in Glasgow. He's a jazz musician as well, and he put on a series of concerts with the exhibition. He asked me to write a piece, but he said, 'I want to improvise, I don't want any music to read, nor do I want a group improvisation, I want a straight ensemble.' I thought, 'This is very unstable chemistry]' There had to be wide parameters, from nothing to everything; total flexibility so that the music could implode or explode according to the soloist's intentions. As director, I wanted to interact with the musicians, like flying a kite and juggling: according to what the kite - the soloist - does, you have to catch a ball, throw another one up. It pushed me into an area I never would have thought of occupying, because it seemed to be the hybrid I'd always tried to avoid.'

As for the symbols which govern the work, 'I sort of deconstruct Alan's painting Bird Gong No 12, transferring the sign-language from the visual to the aural so that it could influence a musical movement. There is a huge gong, a tam-tam, in the middle of the picture: to get that dramatic presence would require a large percussion section as the central focus. Then I decided that the various signs from the painting should indicate the type of material (see guide). I am the link between the soloist, the composition and the ensemble. The soloist has to be absolutely in touch with contemporary extended techniques, aware of the implications of the piece, and with the integrity to work with the music.'

The resulting score is a visual work in its own right which clearly appeals to Alan Davie, who vividly recalls the first performance with himself as piano soloist: 'Barry's score is a lovely thing. I've always been a painter and a musician - to me the two are interchangeable. I gave Barry a strict brief, that the piano part should be completely free. He said, 'How can I write a piano concerto with no piano part?' It's a very exciting score. The piano was so completely dominant, one had the capability of completely altering the music. At certain parts I was almost able to bring it into tonality. It was a great climax to the retrospective of 54 years of my work.'

Barry Guy directs 'Bird Gong Game', with music by Weir and Gorecki, 8pm tomorrow at the ICA, The Mall, SW1 (071-930 3647) pounds 8, concs pounds 6

A silk-screen limited edition of the score is available, price pounds 117.50, from: Maya Recordings, Bramleys House, Shudy Camps, Cambridge CBI 6RA

Barry Guy explains some of the notational symbols used in his graphic score for Bird Gong Game (see illustration above):

SOLO: 'There is a series of solos, which can exist by themselves, or I can pit one of them against the improvising soloist, or I can cut the whole ensemble out and have three soloists.'

TAM-TAM: 'That symbol hung in the middle of the painting, so the tam-tam itself has a central focus within the piece. I have to prepare the percussionist for this solo moment via the trumpet. Once I hold this sign up, the trumpet knows he has to go to the section called 'Way In', as I label it on the score, which has two sets of material, on either of which the trumpet can go in, like Snakes & Ladders I guess. Once that material is complete, the percussionist knows that they are in that particular circle of graphic material: they might look at the hand with the chain and decide that could be rattling a chain; or the hatched lines might suggest brushes, scraping; the small dots and large dots might suggest different levels of dynamic. The implications are of quite a lot of colourful activity: it doesn't suggest something very quiet.'

WILD CARD: 'This invites the players to relate to the improviser, either to go against them, or to go with them.'

MAYBE: 'This is my own little joke: if I have my double bass on the ground next to me, I can join in. In practice there's never any time to do that, because my hands are always busy. As a respect, and a response to Alan's painting, I wanted to set it out in a way which reflected the signs, the layout of his painting. To my mind it reflects the daring quality in his work.'