WILD hair flowing and clad in a black leotard, the gamine figure whirled and flailed her arms while her voice seemed to hit notes no-one else had even thought of. It was 1978. The country was in the grip of punk. But Kate Bush was a sensation.

From the moment she arrived on the music scene as an 18-year-old, Bush appeared to be not just in a different class, but on a different plane. With her debut single, Wuthering Heights, she became the first British female solo artist to reach number one with their own song. And she has gone on to combine commercial success with critically-acclaimed innovation.

But it is now 12 years since her last album, The Red Shoes. It has left her fans desperate for more, and last year rock critic John Mendelssohn published a novel, Waiting for Kate Bush, where a suicidal fan is only restrained from jumping off a tower block by curiosity about her new work.

Such a gap would be career meltdown for any other artist, a sign of creative failure or some other kind of breakdown, but for Bush the normal rules do not apply. Instead, her hiatus is put down to her perfectionism, her artistic experimentation and, above all, her genius.

Today, Bush breaks that silence. The single, King of the Mountain, which has been available for download for several weeks, is released today, and will be followed by the double album, Aerial, one of the most eagerly-awaited records of this or any other year. Although her work now may not have the shock value of Wuthering Heights, both single and album are expected to top the charts, such is her enduring appeal.

Drawing inspiration from literature and classical music as much as any of her predecessors, her back catalogue is a fusion of aboriginal music, Celtic folk, musical theatre, rock and almost any other genre you care to mention. She has collaborated with Eric Clapton, Peter Gabriel, Nigel Kennedy and Prince. Her themes range from incest to a night out with Adolf Hitler. Artists from Madonna to Katie Melua have acknowledged the debt they owe her.

But unlike Madonna, that other 47-year-old musical survivor, Bush has never felt the need to bare her soul. Famously elusive, she rarely gives interviews and has toured only once, in 1979. It was only when close friend Peter Gabriel let slip that she had a son that the world knew of her child, by which time he was 18 months old. Not for her announcing the birth with a fanfare.

This desire to keep her private life hidden has led to comparisons with Greta Garbo, and even suggestions her eccentricity has tipped over into something more, by a culture where celebrity is the only currency and exposure its only measure.

In one of her rare interviews she said: "I think creative control is so incredibly important. I became quickly aware of the outside pressures of being famous affecting my work. It seemed ironic that I was expected to do interviews and television which took me away from my work."

Catherine Bush was born on July 30, 1958, in Bexleyheath, Kent. Her father was a GP who played the piano, her mother a folk dancer from County Waterford in Ireland. Both her older brothers, John and Paddy, were keen folk musicians, and the young Kate grew up with their sea shanties and Irish jigs, an influence which can be heard most clearly in 1985's critically-lauded Hounds of Love.

She took violin lessons at school and once recalled: "I used to play hymns on an old organ in the barn until it was eaten by mice." She was a prodigious talent: at 13 she wrote the song The Man With the Child in His Eyes, later to be a top ten hit.

But she was shy and withdrawn, and at school was bullied for being thin. She once spoke of the fear of being laughed at, which has dogged her all her life. "My father has told me I used to dance to music on the telly," she said. "I was completely unselfconscious and I wasn't aware of people looking at me.

"One day some people came into the room, saw me and laughed, and from that moment on I stopped doing it. I think I've been trying to get back there ever since."

A family friend was impressed enough by her work that he arranged for her to make a demo tape, which was heard by Dave Gilmour, guitarist with Pink Floyd. He, in turn, arranged for an introduction to his record company, EMI.

While today's record executives might have been keen to unleash the 16-year-old on the public, EMI decided she was too young for fame, and instead paid for her to develop her writing, and work with choreographer Lindsay Kemp.

In 1978, they judged she was ready, and at 18 she released Wuthering Heights. Although she has cited Emily Bronte as a formative influence, she is said not to have read the book when she wrote the song, instead relying on the ending of a television adaptation.

But whatever the truth, her haunting voice above a soaring orchestration was more than a breath of fresh air, it was a windswept moor, desolate and beautiful. Only marginally less well-remembered is her theatrical interpretation of the song, pressing with her hands against an invisible window before flinging her arms around her head, still an instantly-recognisable impression almost 30 years on.

The same year saw the release of two albums, The Kick Inside and Lionheart, and the following year she embarked on her only tour, accompanied by a troupe of jugglers and dancers.

Almost from the start she took complete creative control over her work, now entirely studio-based. Her work has defied the convention of regular albums: three years separated The Dreaming, featuring Rolf Harris on didgeridoo, and The Hounds of Love, four between the latter and The Sensual World and another four until The Red Shoes.

Her eight albums and myriad hit singles have earned her an estimated £25m and she lives on an island in the Thames near Reading, with its own 48-track recording studio. She also has a house with its own private beach in Devon. She owns the bulk of her many companies, with the rest owned by her brothers.

She has a son, Bertie, with her partner, musician Danny McIntosh, but suggestions she is a tortured recluse are dismissed. In a recent interview, she said: "The reclusive thing is because I don't go clubbing and I don't do a lot of publicity. I'm a quiet, private person who has managed to hang around for a few years."

And she said she was keen to keep Bertie out of the spotlight. "I am just trying to be a good protective mother," she said. "I want to give him as normal a childhood as possible while preserving his privacy."

But now her temporary exile - previously broken only rarely - is over and she will face the circus again. For her fans, it is a moment they have been anticipating for more than a decade. For everyone else, it is a chance to see what a prodigious and truly individual talent can achieve.

l King of the Mountain is released today. Aerial is released on November 7.