The modern music man

The adagio of Beethoven's ninth symphony has a comparable effect, as do the start and finish of Tristan and Isolde, moments in Debussy's La Mer and Janacek's In the Mists, and The Beatles in Norwegian Wood. But Birtwistle is the only one who does it as a matter of course, one work after another. Not that everyone appreciates his onslaughts.

The last time he brought an opera to Covent Garden there was an organised riot by self-styled Hecklers. When a wild piece called Panic was played at the Last Night of the 1995 Proms, the BBC switchboard was jammed as viewers complained that it upset their fireside pets. His music is never an easy listen nor a trivial pursuit. It resists formal description. Neither technically atonal nor arrestingly tuneful, it dredges from the bowels of the earth a panoply of sound that both terrifies and transfixes, unfolding with the drama of an auto-da-fé or a public hanging.

His newest opera, The Minotaur, goes further than ever before into the schism at the heart of human nature, the animal within us. Yet to meet this mild and furry man, twinkle-eyed, sotto voce and self-deprecating, you would never imagine the roars he can unleash.

Proprieties first. He is Sir Harrison Birtwistle, CH. He was minded to refuse royal honours, but establishment figures persuaded him "it would be good for music", so he acquiesced. Harrison is a gritty Lancastrian forename, from the scrubland outskirts of Accrington, but he's Harry to his friends. "Shirty Birty" they called him at school, a solitary lad, his head a whirl of Greek mythology and a wail of clarinets. At 11 years old, he once told me, "I heard a music that didn't exist." He has been chasing it with unerring certainty ever since.

At music college in Manchester, he was the slow-coach in a brilliant crowd of Peter Maxwell Davies (now Master of the Queen's Musick), Alexander Goehr (retired Professor of Music at Cambridge) and the pianist-composer, John Ogdon.

Harry was well into his thirties before he put his music before an audience, only for Benjamin Britten to huff out of the 1968 Aldeburgh premiere of Punch and Judy, outraged by its physical and aural violence. Last week at the Linbury there were adults-only notices at the box-office window, as if the work were somehow morally harmful. At the Young Vic in April, the second new production within a month is restricted to over-16s.

I got to know Birtwistle in the mid-1980s when he was living with his wife, Sheila, on a bare French mountain, writing Mask of Orpheus and Gawain in a landscape where sour-faced sheep passed for company.

The sound, he showed me, did not come easily. It took him three days to fill a single sheet of music, dotting and erasing until what appeared on paper matched the noise in his head. One night he rang his librettist David Harsent, at home in Fulham. "David," said Harry, "you know the bit where the knight's head comes off ? Well, it's going to have to come off three times. The music dictates it." With Birtwistle, there is no arguing with what the music wants.

ALLof his operas are rooted in myth and ritual, Greek, English and Christian. In The Last Supper, conducted by Daniel Barenboim in Berlin, he courted controversy with a revisionist depiction of Judas, whom Christ seeks to reconcile. It was a further risk to stage the premiere at Easter in 2000.

However, rather than offend, The Last Supper provoked strong debate about the sources of Christian anti-Semitism and the role of the scapegoat in organised religion. Only Birtwistle would have defied musical logic by writing for chamber orchestra without violins, outlining the Biblical characters in merciless relief.

In The Minotaur, which opens at Covent Garden next month, he explores "the duality in us all, half-man, halfbeast". Harsent sees the beast as Jekyll and Hyde, Birtwistle as a whole man troubled by animal urges. The bull is trapped in a labyrinth, roaring violence. The tension is inherent. "The story has never been a candidate for theatrical success," says the composer. "I won't tell you how it resolves."

I ask him why he sticks to myth - is the real world so uninteresting? "I wouldn't know how to respond to contemporary events," he replies in slow, flattened vowels. But the question troubles him and he returns to it minutes later, working cyclically towards an answer as he does in music. "I am of the world," he insists. "In that sense the work is relevant to my time. There are certain things in life you don't have to justify. My interest in myth is fundamental, ever since I was so high. But first there is the music. The subject matter has to fit the music. Naturalism would not fit. That's why I write myths."

On the Covent Garden website for a premiere that is more than halfway sold out, there is a photograph of the composer in rain jacket cosying up to a bull sculpture by the Bristol artist Beth Carter. There is no pomp to the man, and much fun. His operas are speckled with little jokes, musical and verbal. He is widely read and visually literate, an exhilarating companion.These days he tends a long garden in Wiltshire, made to his design, every plant bedded by his own hand.

Year by year, his music is catching on. In Berlin, Chicago and Cleveland, he is a fixture of the orchestral season. Each new work is a step forward from the last, each an electric shock. At 73, Harrison Birtwistle defies easy categorisation. As one of the few musicians who change the way we listen, he stands comparison with Beethoven and Wagner. He is certainly the most original composer at work in Britain today, perhaps anywhere on earth. If you don't believe me, go to The Minotaur, then hear the dawn chorus.

The Minotaur premieres at Covent Garden (020 7304 4000, www.roh.org.uk) on 15 April (in rep until 3 May); Punch and Judy is at the Young Vic (020 7922 2922, www.youngvic.org)19-27 April.