Michael Nyman: If sex-comedies and violence don't do it, then try a touch of Tourette's

He finds music to be a rich but limiting form, so what is it that keeps Michael Nyman composing music at such a prodigious rate, wonders Nick Kimberley

Composers, we might assume, love putting notes on paper. Music defines their relationship with the world, so it's rather surprising that Michael Nyman, a prodigiously prolific composer, thinks that "music is very rich, but it's limiting. There are worlds out there that you can't necessarily put into a string quartet or a piece for orchestra."

Nyman is not suggesting that the string quartet and the orchestra are somehow inadequate media; he has written four string quartets and many works for orchestra, as well as any number of pieces for his own custom-built Michael Nyman Band. Nevertheless, it is his work for the movies that has brought him his widest audience. He has provided scores for some 30 films, beginning with the gleefully titled sex comedy Keep It Up Downstairs in 1976. His famously successful collaboration with Peter Greenaway saw him write music for 10 films between 1977 and 1991, including The Draughtsman's Contract and The Cook, The Thief, His Wife and Her Lover. Since then he has written for such diverse movies as Jane Campion's The Piano, Andrew Nicol's Gattaca and Michael Winterbottom's Wonderland.

Yet the relationship between film and music is too constricting for Nyman to consider himself a film composer; rather he is a composer who sometimes writes for film. "Usually, the film's director has a particular vision of what the music should do, so you're constantly cramped. You try to squeeze as much interest, energy and variety from those limitations as you can, but often you're involved in films that don't excite you. It was different working with Peter Greenaway. There were things in his films that turned me off. The violence in The Cook, The Thief, His Wife and Her Lover, for example. Nevertheless, there was an affinity of working practice, of attitude and subject matter. He gave me carte blanche, and that allowed me to write probably the most diverse music that any composer has been allowed to write for film."

But if writing for film is not his chosen métier, and music alone is "rich but limiting", what is Nyman's most nearly ideal form? The answer can be found in that part of his work-list headed opera. It contains just two works, The Man Who Mistook His Wife for a Hat, first performed in 1986; and Facing Goya, premiered last year in Spain. (A third work, Noises, Sounds and Sweet Airs, bears the description "opera-ballet".) Yet it is precisely opera's potential to contain "worlds out there" unavailable to the string quartet and orchestra that most attracts Nyman: "I love using the voice, and as soon as you have two voices singing, not as presenters of text, but as characters, there is a social and emotional interaction. That's what makes opera as exciting for me as a composer, as a feature film would be if I was a film director: it allows you a kind of intelligence in dealing with matters from outside music."

It is a mark of that intelligence that Nyman's operas tackle subjects not normally regarded as operatic. The first, The Man Who Mistook His Wife for a Hat (a new production of which opens in London next week) derives from a chapter in Dr Oliver Sacks's book of the same name: when one of Sacks's patients, a musician, loses his ability to recognise familiar objects, his musicality becomes his only means of coping with his psychic disorientation. The nature of the subject invited a musical response, but it required a particular sensibility to make an opera from a neurologist's case study.

Facing Goya, on the other hand, derives not from a single source, but from a range of Nymanesque preoccupations: craniometry, gene therapy, cloning and the work of Goya are just four of the elements that it juggles. "With Facing Goya," Nyman suggests, "I was dealing with body fascism, genetics, eugenics, science used for politically skewed purposes. My own intellectual inquisitiveness then had to be passed to my librettist, Victoria Hardie, who put it into a dramatic form shaped by what interests me. There is no existing package that contains the ideas, such as a play or a novel. When Facing Goya toured in Spain, there were the usual opera appreciation noises about the singers, the set, the direction and the music, but there was also debate about the issues that the opera engaged in. Opera isn't a question of merely sitting down to be told a story. It should be more than that."

Nyman regards Facing Goya as "the best work I've done, the most representative and in a way the most surprising". Responses to the performances in Spain suggest that he's not wrong. Meanwhile he is at work on another opera with a Sacks connection; this concerns a man with Tourette's Syndrome. "It has to do with disability and exclusion, and the process of putting Tourette's as an illness within a larger social and political context," Nyman says. The Tourette's opera will have its premiere in Germany, while the new production of The Man Who Mistook... is by a Norwegian company. Facing Goya has only been seen in Spain. Opera companies in this country have not so far beaten a path to Nyman's door.

While opera remains the most seductive medium for most composers, the small number of successful new operas suggests that it also remains the most elusive. As Nyman readily points out, "I've proved I can write opera. It would be nice to do an opera in an opera house in this country." I think we can take that as an open invitation.

'The Man Who Mistook His Wife for a Hat': Lyric Theatre, Hammersmith, W6 (020 8741 2311), 20 to 23 June. Michael Nyman is featured composer at the Harrogate International Festival (01423 537 230), 19 July to 4 August