It's the year of the snake. And while Ang Lee's sumptuous martial arts film, Crouching Tiger, Hidden Dragon, has summoned up magical images of a hidden past, on the small screen the National Geographic Channel is busily uncovering stunning footage of an unsuspected present. China is turning up everywhere - but the last place you'd expect to find a Chinese connection is in a recital by a British viol consort. Still, there it is on the programme: Tan Dun's A Sinking Love, five minutes of glorious swooping and sliding, and some distinctly snake-like aspirations disappearing into the undergrowth with a virtuoso flick.

On the other hand, Fretwork - aka violists Richard Boothby, William Hunt, Richard Campbell and Susanna Pell - has turned the unexpected into something of a habit. And so the programme for the group's forthcoming tour of Ireland will include, alongside music by William Byrd, Orlando Gibbons and the aforementioned Tan Dun, a piece by Elvis Costello called Put Away Forbidden Playthings. What's all this then? Aren't viol consorts supposed to specialise in nice, polite "early" music? Definitely not, retorts Richard Boothby. Not at the start of the 21st century.

"Contemporary music ought not to be a specialism either; it ought to be what people play. I mean, at this point in time, there's nothing particularly `early' about Purcell or Bach as opposed to Schubert or Brahms," he says. "Brahms died two centuries ago now - so you could say Brahms is early music.

"Stravinsky is early music. Even modernism is `early' now; it's not the music that's being written today. So once you consign music to a historical box, it doesn't matter which box you open really."

As a creature of the 16th century, however, the viol can hardly hope to escape its past. A kind of bowed lute, it has a fretted neck and a flatter bridge and more steeply sloped shoulders than the violin.

"The name comes from the Portuguese vihuela, an antecedent of the guitar. In fact, the Portuguese still use a form of this instrument in their fado bands," says Boothby, a cellist who became interested in the viol while finishing off a thesis on Wagner at university. "This was in the early 1970s, and there was a shop called The Early Music Shop, which had some rather basic instruments for sale. As interest in that musical period was expanding rapidly, new makers of viols were just starting out, to satisfy the demand. Old instruments tend to be rather expensive to get hold of, but we have a couple of treble viols that are original English instruments from around 1600."

The idea of forming a viol group arose when, along with William Hunt and Richard Campbell, Boothby toured with Andrew Parrott's Taverner Consort. The word "consort", an old spelling of "concert", refers to any body of performers playing together - a suitably openended definition for Fretwork, which expanded from its original threesome to a six-piece band, but which often (as on its Irish tour) performs as a quartet. In its early years, the group concentrated on baroque repertoire, but in 1990, a phone call from the English composer, George Benjamin, changed that.

"He had heard one of our records and thought the sound was completely different from anything he'd heard before," says Boothby. "He wanted to write a piece for us."

This was something of a surprise, for while Fretwork's members had varied musical backgrounds - one had played electric guitar - none had any particular grounding in contemporary music.

"But the piece he wrote for us, Upon Silence, was so extraordinary and such a mindboggling piece, it really turned us on to contemporary music," says Boothby.

Since then, they have commissioned various pieces, including, as part of a project to celebrate the tercentenary of Purcell's death in 1993, those by Tan Dun and Elvis Costello. Composers were asked to come up with "miniatures" for counter-tenor and viol based on Purcell's fantasies. The resulting pieces, recorded on Fretwork's 1997 CD, Sit Fast, with soloist Michael Chance, comprise an astonishing array of explorations in sound.

The two pieces chosen for the Irish tour - on which the soloist will be soprano Julia Gooding - could hardly be more contrasting. Costello's Put Away Forbidden Playthings begins with an instrumental introduction in a deceptively Purcellian style, gradually slipping dissonance into the mix but retaining an elegiac intensity. The lyric, according to the composer, "laments the interrupted access to the musical possibilities of the music of Purcell's time".

Tan Dun's A Sinking Love, a setting in Chinese of a scrap of verse by eighth-century poet Li Po, uses a six-note quotation from Purcell as the base for a gentle, yet dazzling, voyage into articulation. The strings play only in harmonics, while the vocal line echoes both the style of the Peking Opera and the way in which the meaning of a word in the Chinese language is related to the pitch inflection.

Placed next to Purcell and Bach on a programme, these new works are a potent illustration of just how versatile the viol can be.

"It's nice to be able to break up a programme of old music with contemporary music, or vice-versa, because the modes of expression are very, very different," says Boothby.

But are there limits to what the viol consort can do? As a former Wagner fan, does he harbour secret dreams of playing Siegfried with a big, bear-like tenor?

"Not with the viol, really, no. I still like listening to Romantic music and I'm still a big Wagner fan - not that I have any time to listen to Wagner these days. But playing it would be another matter because mainly it's big orchestral music and any part you could play in it would be relatively small," Boothby says.

Far from harking back to the past, he is convinced that the viol consort, along with other modest groupings such as trios and quartets, may well be the musical medium of the future.

"I think in a couple of hundred years from now, the 19th century and the first half of the 20th century - from Mozart through to Stravinsky - will be seen as a very unusual period in music where people assembled these enormous forces, symphony orchestras, to play music," he says.

"Orchestral music is really finished. People don't really write orchestral pieces any more, except when orchestras commission it, obviously. The death of the orchestra is imminent and we're living through its death throes."

Fretwork's ESB/Music Network tour begins at the Sirius Arts Centre in Cobh tonight and moves on to Kilkenny tomorrow, Dublin on Thursday, Tinahely on Friday, Mohill on Saturday, Donegal on Sunday, Belfast on Wednesday, February 14th, Antrim on Thursday, February 15th and Armagh on Friday, February 16th. For information, phone 01-6719429.