MacGregor's itinerary is proof of the eclecticism for which she's well known. In August, she performed alongside samplers (at the Punkt Festival in Norway); in November, she was in a concert dedicated to electronica (at Liverpool's Cornerstone Arts Festival, including a performance of Jonathan Harvey's Tombeau de Messiaen).

And in the past week she performed a mix of Satie, Schumann and Count Basie, a Gershwin concerto and preludes with the BBC Concert Orchestra in London, and an evening in Italy where Art of Fugue was followed by Moondog's Sidewalk Dances.

MacGregor will mine a different oeuvre when she appears this week at the Hong Kong Arts Festival, where she is scheduled to play Olivier Messiaen's Vingt Regards sur L'Enfant Jesus. The 135-minute, 20-movement work requires great stamina and delicacy to recreate the late French composer's mix of ethereal leitmotifs, near-mathematic symmetry, and the nuanced rhythms permeated with the colour of Indonesian gamelan and Indian raga.

MacGregor says she has been devoted to the work since she was first introduced to it at a Messiaen masterclass she attended as a student. The piece, she says, was in line with her interest in 'big contemporary music pieces which were very epic in scope - I was very attracted to the idea of a piece that could be a whole world like that, there's a whole universe in there'.

MacGregor also found a kindred spirit in Messiaen, who absorbed influences across geographical and artistic barriers, as seen in his adaptation of non-western musical structures and birdsong, for example, or his advocacy of the Ondes Martenot, an early electronic musical instrument with a keyboard and slide, invented in 1928 by Maurice Martenot.

'He's just somebody who's very culturally aware of a lot of very different philosophies and music from around the world, and it allowed him to really deeply influence how he wrote. He was one of the first composers to be so very open about that,' says MacGregor.

'I think it's probably the role of an artist not to be too rigid or narrow-minded, and obviously I play an unusually wide repertoire and I collaborate a great deal, but I think in general artists can be very open-minded.'

Play, MacGregor's most well-known album from 2001 and a shortlist for Britain's Mercury Prize, is testament to her willingness to venture into uncharted artistic waters. It is a collection of 15 pieces written by a diverse cast of composers: numbers by Bach and Byrd, and by old-time experimentalists such as Piazzolla, Nancarrow, Charles Ives, Gyorgy Ligeti and John Cage are placed next to pieces by young composers such as Alasdair Nicolson and Ivana Ognjanovic, and collaborations with South African jazz pianist Moses Molelekwa and British dance music boffin Talvin Singh.

With her next record, Neural Circuits (2002), she moved beyond just a transgression of norms in musical tones. The title track, written by Nitin Sawhney, is a high-octane ensemble piece that brings to mind images of social chaos, and features snippets of news bulletins about Washington's hawkish pronouncements after the terrorist attacks in September 2001.

The political undertones and the track's immediacy to what is unfolding in real-life - what with the US-led coalition sweeping into Afghanistan on its so-called war on terror - unnerved many critics when it was premiered in a live setting, MacGregor says.

It was a creative decision that's vindicated, she says. 'I was determined to put the music on disc and call the album that,' she says. 'And when the album came out 18 months later, when the nervous and unhappy reaction to the piece had all died down, those same critics were writing glowing reviews.

'It's an interesting psychological study, in that when people are put on the spot, they expect classical music to be soothing and comforting, a little bit abstract but not at all to do with things around you.'

MacGregor's liberal take on classical music, art and life can be traced to her unique upbringing. The daughter of a Seventh-Day Adventist preacher, she was home-schooled until she was 11, with her mother tutoring her on the piano.

'The crucial thing was that until then I was left alone and had an individualistic sense of music, art and maths,' MacGregor says. 'And there's the running around in the park - all the things that children do, and it wasn't that heavily 'civilised'.'

Free from conforming to peer pressure as a young girl, she 'was able to pick up books and read about a huge range of musicians and their music'. She says: 'My favourite music book would be one that could tell me about Mozart and Oscar Peterson at the same time, and I was able to absorb an incredibly wide range of music without being told that there was something wrong about the choice I was making.'

Her subsequent life was more conventional - a degree at Cambridge, followed by more studies at the Royal Academy of Music in London - but her independent streak was set. And it shows, not only with her now trademark braided hair, but also in the way she releases her music through her own label Soundcircus, and her rejection of the airport hotel-room routine of many travelling musicians.

'I was very fond of jumping into a car and driving across America, and I found myself quite a lot of times in New Mexico, which has an incredibly interesting environment,' she says.

In the past year she has visited Argentinian musicians at work and explored Moscow's vibrant jazz scene, she says. She's not going to while away her five-day stay in Hong Kong as an ordinary tourist, either.

'I particularly want to explore the visual arts scene in Hong Kong.'

She has also written a series of music books for children and been a director of the Bath Music Festival, so she's serious about her meet-the-artist session the day after her concert. Rather than just ruminate about Vingt Regards and her career, she also intends to show DVDs of her multimedia work, including a project she did last year with paediatricians and artists about premature birth.

'I think there are still people who expect classical music to be a soothing warm bath, and they tend to forget the origins of classical music is far more tempestuous and far more interesting,' she says. 'If you look at Mozart, whose work was quite political and quite a sign of his times, he didn't shy away at all from writing things that are politically obtuse.'

With her unceasing creativity, MacGregor should serve as a good reminder of that.

Joanna MacGregor plays Vingt Regards sur L'Enfant Jesus, Mar 8, 8pm, City Hall Concert Hall, Central, HK$80-HK$320 (adults) and HK$40-HK$160 (students)