Drawing from familar standards by John Coltrane and Herbie Hancock as well as her own compositions, Yeoh grew in confidence throughout the performance until, by the end, she was flying. She also interspersed the tunes with ironic references to television game-shows and children's programmes in a way that really seemed to bring jazz's long-lost tradition of re-inventing popular music into the present. And importantly, she revealed a winningly sparky personality. "This is somefink I made up meself," she would say by way of introduction, before going into an extempore ramble, as avant- garde as the experiments of free-jazz pianist Cecil Taylor. It was the best gig I'd seen all year, bar none, and on the strength of it I made her this newspaper's Jazz Musician of 1996.
Even now only 24, Yeoh has yet to make an album, but she's going to be a star. On Friday she performs with her big band, Infinitum +, at the Purcell Room, as part of the Oris London Jazz Festival, in the reprise of a commission from this year's Bath Festival. Reinforcing the sense of the present rather than the past, where jazz usually resides, Yeoh's background is emphatically that of contemporary London. "My dad's Malaysian: one half Chinese, one quarter Thai and one quarter Burmese," she says, "and it's two different types of Chinese as well. Spiritually, I think we're all from the same place, and I try to reflect that in my music. But being of dual heritage obviously affects the way I compose, and being in Britain will give it a different groove."
She speaks a little Mandarin as well as fluent Italian, and her interest in languages provides the raw material for her compositions, in which she harmonises the patterns of everyday speech into musical form. Previous efforts have involved re-orchestrating the theme from the Magic Roundabout - plus Dougal's voice - for her trio, and the piece she will play on Friday developed from a recording of six people reading, in six different languages, one of her own poems. The speech-rhythms were then harmonised into parts for the band, and a video projection of the readings will accompany the music.
Yeoh learnt to play the piano at the age of three. "I used to knock out a few little tunes on a toy piano to entertain the family, and I'd hear things on the telly and try to repeat them, and then my parents thought I should have lessons," she says. "When I was seven, my grandad bought me a piano; he was a London cabbie and he collected his tips to pay for it. My childhood was good, with typical working-class Sundays when they'd have a roast dinner in the afternoon then have a few Guinness, and crash out while I'd be tinkling away. I was an only child, and I'd be saying to my mum 'Let's go out and play', and she'd say 'Leave me be, I'm drinking me Guinness'. So I'd go and play the piano."
She attended Islington Green school, and went to Saturday music lessons given by the jazz trumpeter Ian Carr at his weekend school in Kentish Town. After completing one year of a music degree at Goldsmith's, her first break came at a jam session at the Jazz Cafe in London with Courtney Pine, sitting in for a pianist who hadn't turned up. It led to her joining Pine's band and immediately going off on an international tour; later she joined the band of pop star Neneh Cherry before forming her trio Infinitum + with bassist Michael Mondesir and drummer Keith Leblanc.
Being a female jazz musican isn't, she says, easy. "Any woman who starts in jazz must be true to it, because it's so hard. People say that you can exploit your sexuality, but you can't do that and be true to your art at the same time; it has to be one or the other. People expect women to be a symbol of their sexuality or their femininity, but I'm just there playing the spirit of the music. If people are really checking the music, my sex shouldn't bother them."
The future is wide open, and she has already established the basis of a parallel classical career by writing for Piano Circus. A full-blown symphony could be on the cards in five years' time. "It's that whole thing of the internal clock and I can only really envisage the next year or two,", she says. "I've only really been going for three years, so may be after another three I'll be able to predict the next six. Also, I'm a woman and there's babies and things, y'know? We're born knowing that kind of stuff. There's so much to think about, and then to forget about and just play, in the moment, 'cos that's how the music comes out."
Nikki Yeoh's Infinitum +: Purcell Room, SE1 (0171 960 4242), Fri.