New chapter in the Stockhausen story

When a composer dies, so does his music. Performances tend to fade out in the decade after the funeral, allowing the reputation to find its place in the canon and musicians to reassess the work without the overbearing presence of its creator. So it was with Britten, with Shostakovich, with Messiaen, with Ligeti - just don't expect Karlheinz Stockhausen to play by the same rules.

The German composer, who died at the weekend aged 79, spent the last third of his life clawing back his music from public consumption. He broke with his publisher, Universal, then with his record label, Deutsche Grammophon, insisting that he alone had the right to exploit his genius. Scores and records could still be obtained from his own Stockhausen Verlag, based in a muddy village outside Cologne where the composer lived with two adoring female companions, the clarinettist Suzanne Stephens and flautist Kathinka Pasveer, in the manner of the Indian maharishis he once admired.

Laying hands on the music was neither cheap nor easy. The cost of a two-CD opera can run to $85, and the Stockhausen website does not accept credit cards. Arranging a live performance involved obtaining personal permission from the master and his handmaidens. One of the formative catalogues of post-War culture was being dragged into oblivion, while its composer enjoyed increasing celebrity.

Some 7.8 million people have visited his website over the past decade, demonstrating the immensity of his influence over such diverse musicians as Miles Davis, Bjork, Frank Zappa and the Beatles. Yet the bigger his myth, the less the world heard his music.

What happens next is life in reverse.

The Stockhausen estate will be assessed for probate for the benefit of six children, two ex-wives, members of the commune and other claimants. Auditors will find that his copyrights have been seriously under-utilised and the executors will come under pressure to seek music industry partnerships for the exploitation of 362 works. There will be a spate of international bids and a flood of unheard Stockhausen, starting at what would have been his 80th birthday next August. It may be that Karlheinz Stockhausen had to die in order that his music might live.

How much of it is worth hearing is a matter of contention. Posterity will remember Stockhausen chiefly as the man who wrote the first piece of electronic music that did not sound like a bad telephone line in a thunderstorm. It will also remember him for a megalomania so vast that it sought to outstrip Richard Wagner with an opera lasting 29 hours and played over seven nights, a proposition so out of tune with the rhythms of its century that major houses lost interest before it was halfway done.

This was the core paradox of Stockhausen - a genius at simplifying extreme complexity and, at the same time, in dressing up the simplest of ideas in a monumentally superfluous construction-Raised under a Nazi regime which murdered his mentally-ill mother in its euthanasia programme, he saw the light of modernism at the Darmstadt summer school in 1951. He became a pupil of the French mystic Olivier Messiaen, who proclaimed him and Pierre Boulez leaders of the musical future.

Unlike Boulez, who retreated into evertinier cells of atonal mathematics, Stockhausen explored the physics of music. In Gesang der J¸nglinge (the small boy's song), he modulated the voice of a boy chorister from Cologne Cathedral against an electronic track to the point where one became indistinguishable from the other, achieving a magical fusion of real and surreal.

Its impact was universal. Gyrgy Ligeti, hearing the first broadcast in 1956 as Soviet tanks rolled through Budapest, fled the country and turned up at Stockhausen's apartment, where he lived for several months. The Beatles, a decade later, included the head of Stockhausen on the cover of Sgt Pepper's Lonely Hearts Club Band (back row, fifth from left). West German Radio built him a studio for personal use in Cologne, but Stockhausen was not to be confined to electronics.

In 1959, he explored the spatial dimensions of the concert hall in Gruppen, written for a scattered ensemble with three conductors in different parts of the hall. In Mikrophonie (1964) he introduced live electronics; in Hymnen (1968) he experimented with Indian mantras and Californian minimalism.

Like many post-modern artists he delegated some of the details of composition to assistants in his ménage. Boulez, as chief conductor at the BBC and the New York Philharmonic, showered him with opportunities but Stockhausen's mind was turning to his magnum opus, the seven-day opera cycle Licht, which, in early episodes at La Scala and Covent Garden, mingled attractive music with stretches of interminable tedium. In the segment known as Thursday, a trumpet played on the opera house roof. In Wednesday, a string quartet tried to make itself heard from an airborne helicopter.

Stockhausen was drifting by now beyond rational discourse. When I proposed a newspaper interview with him 15 years ago, he accepted with alacrity; only to add that any tapes and the very words he spoke would have to remain his property in perpetuity, because a man of his singularity possessed an "aura" that could not be relinquished.

In September 2001 he attracted widespread condemnation for describing the attack on the New York twin towers as "the greatest work of art imaginable". Isolated, adulated, fenced in by his own myth, he left the final two days of his opera unfinished and apparently unwanted. Yet, with his death, the story of Stockhausen is about to begin all over again.