In a masterclass at Dartington International Summer School of Music last month, 30 professional pianists queued for audition. They came from all over the world and some played superbly, but one of the most dazzling was a quiet girl who delivered a horrendously difficult Prokofiev sonata with serene authority.
When it was her turn to go under the tutorial hot light next day, she chose a Liszt piece which is normally guaranteed to fall apart unless the player is in total control. She held it together with nonchalant ease, and let its poetry speak.
"Fine", said Joanna MacGregor, the masterclass tutor, when she'd finished, "but your playing is too careful, too polished. Let's have it again, and make the whole thing more extreme." Whereupon she did, with such passion that if you'd closed your eyes you'd have thought it was someone else. And still scarcely a note out of place. The round of applause when she had finished - from a breed normally famed for their competitiveness - was genuinely admiring.
Alison Farr turns out to be a 15-year-old from Bournemouth who is well advanced on the road to stardom, though you'd never guess it from her unassuming manner. Closely chaperoned by her mother, she answers my questions with simple, factual directness. She started playing at five, and passed Grade VIII - the Associated Board's pre-professional exam - with distinction when she was 10. Last year she was voted Audi Junior Musician of the Year. On October 8 she will play Grieg's piano concerto with the London Philharmonic Youth Orchestra at the Queen Elizabeth Hall. This coming Monday she is playing in Bristol, where the semi-finals of the BBC Young Musician of the Year competition are being held.
She is a boarder at Wells Cathedral School, and is taking GCSEs in English, French, German, maths, and music this year. She practises two or three hours a day, and periodically goes to the Royal Academy for weekend lessons. What, I ask her, did she make of Joanna MacGregor's judgment on her first attempt at the Liszt? "Very useful." Was she nervous? "A bit." Is she nervous on the concert platform? "No. Never."
Which seems to be the end of the interview, until her mother remarks that Alison has been too modest: she actually first played the piano at one-and-a-half. "She just went up to it and played a tune straight off - from Beethoven's Choral Symphony, which she'd heard on the radio. My husband immediately said to me, 'Now don't get any ideas'. She was our third child, and the older two had struggled at the piano for years, and still weren't any good. But from that moment on she kept pestering me for lessons, so I started to teach her myself." She started formal lessons at five, and announced at seven that she was going to be a concert pianist when she grew up.
She played other instruments too: the flute well enough to get another Grade VIII, and the violin to almost the same standard. At nine she started playing the harp; she also played the recorder and guitar. It was only when she went to Wells that she was made to specialise.
Her performance of the Liszt was characteristic, her mother adds. "She's always very contained when she's in a teaching situation. But put her on a concert platform, where there's no teacher around, and she lets herself go completely."
Apart from the chaperoning mother, Alison Farr seems poles apart from the super-worldly violinist Vanessa-Mae. But in many respects she is an absolutely typical member of nature's musical elite, who share so many traits in common that one is tempted to wonder whether their similarity is genetic.
Consider, for example, the young Russian violinist Maxim Vengerov, whose mother used to silence her hungry baby by turning on the tape recorder. "Music," he says now, "was for me a replacement for food." At four he announced that he wanted to play the violin, so his mother took him to the best teacher in town. For their first two visits he stubbornly refused to play, but when he saw how this pained her he relented. "In my third lesson, I played 80 songs by heart, and my teacher said, 'We have a genius!'" He gave his first concert at five, playing some Paganini variations "which were very easy for me".
"I was born with music in my system," said the legendary violinist Fritz Kreisler. "I knew musical scores instinctively before my ABC. It was a gift of Providence. I did not acquire it." The Korean violinist Sarah Chang made her New York debut with Paganini's first concerto - and without a rehearsal - at the age of eight. Zubin Mehta, who conducted the concert, concluded that she was quite simply a reincarnation. "She must have learned it all in a previous life."
Christopher Potts, director of music at the Menuhin School in Stoke D'Abernon, Surrey, accepts that - taking co-ordination, concentration, and memory for granted - there is an element that can't be explained. "All we can say is that music is part of nature, and that nature has endowed these children with a special gift."
Precocious musical wisdom is another trait which Farr shares with other prodigies. Vengerov insists that now, at 22, his musical interpretations have not changed: "I was the same person then as I am now." Sarah Chang says that in her view, age is irrelevant. "People say that you must experience life and the great emotions, before you can understand great music, but I disagree with that." Her teacher Dorothy DeLay makes the point in a different way. "Children experience passion in a much purer form than adults. And they aren't weighed down and dulled by experience."
Many prodigies are the offspring of musicians, or come from very musical homes. In contrast to Farr, however, some are propelled towards stardom by brute political and economic forces: one needs no further explanation for the amazing proliferation of Jewish violinists who came out of Odessa in the early years of this century. Reading Yehudi Menuhin's autobiography, one is struck by his indomitable will. And one is keenly aware of the parental will that drives him: defiantly branded by his Russian parents - Yehudi simply means Jew - he was pre-ordained to carry the torch for both his race and his talent.
The predominantly female prodigies who have recently emerged from the Far East could be said to be escaping from a ghetto of a different sort, though their ghetto is a sexual one: oriental tradition still holds its girls in check.
Alison Farr's multi-talentedness, on the other hand, is once more typical of the breed. As Menuhin points out, "Adults greatly underestimate the capabilities of children." Yi Wang, one of the up-and-coming young violinists at the Guildhall School of Music, nearly became a ping-pong pro. Vengerov is a keen sportsman. The young American violin virtuoso Joshua Bell could easily have been a pro at either tennis or golf. Sarah Chang's one sadness has been her enforced farewell - for reasons of risk - to her other great passion, gymnastics. As DeLay observes, "It's not generally realised that these are people of quite extraordinary health and energy."
As the Dartington masterclass wait for their final session, I notice that one of the recumbent figures is quietly juggling three balls in the air. I might have guessed - Alison Farr. Easy, she says, and offers to add two more. As the five balls circulate, and a little grin appears on her face, I feel not so much envy as sheer bemusement. Talent is a strange thing, and there's absolutely no justice in the way it's handed out.