Pioneers on the World music frontier, Capercaillie have drawn in new sounds and new members unafraid to take risks. It's the key to their success, they tell Siobhán Long

If only there were commission rates for musicians, Capercaillie would surely have lined their pockets with silver many times over. Because much of what we hear as "World" music on the airwaves owes at least some of its airtime to the pioneering efforts of this Scottish outfit who've been on the road some 18 years - with ne'er a sign of a homicide nor a hint of drug-fuelled or frenzied lost album in their collective biography.

Back in the dark days of 1979, when radio DJs were in recovery mode from glam rock, and had little more to look forward to than the new romantics (Duran Duran, Spandau Ballet et al), a little revolution was afoot in Argyll in the Scottish Highlands. Donald Shaw, keyboards and accordion maestro and Karen Matheson, vocalist and gatherer of songs from deep in the crevices of Barra, the island home of her grandmother, thought it was high time they aired the traditional music of their home place.

Joined by Manus Lunny and his bouzouki, and by Charlie McKerron with his fiddle, Capercaillie's first steps out into the world were taken by this skeletal quartet hell-bent on stretching the outer limits of both their traditional repertoire and their imaginations.

The last two decades have seen Capercaillie, (named after a large grouse) sample drum loops, multi-tracking and all manner of rhythmic hiccups as well as stripping the music back to its bare bones on their last album, Nadurra.

Their 2003 appetites have sent them searching for fodder of a richer texture, and this year's Choice Language is as urbane an affair as you'll encounter this side of a Swiss finishing school - or an Evelyn Waugh saga.

Donald Shaw, Capercaillie's accordionist, pianist, keyboardist, programmer and backing vocalist, still conjures the same passion for the music, and for the process of recording that he did back in the late 1970s when the band took their first tentative steps into the studio. Replenishing Capercaillie's resources with new sounds and with musicians who aren't afraid to take risks is key to the band's bracing state of health, he admits.

"I think we felt a wee bit short-changed after Nadurra", he discloses, "in that we made quite a quick album acoustically, and one of the things was that Charlie  and I had just started working with Michael McGoldrick [Mancunian flute, pipes and whistle player], and for us that was a sort of a reincarnation when Michael started playing with us. It felt like we'd got slightly jaded at that time.

"We had been concentrating much more on song a lot, so over the last three years, we developed a great relationship with Michael and we wanted to be a bit more adventurous then when it came to recording this album."

Repertoire has always been key to Shaw & Co's identity. Laden as they were by a brace of songs courtesy of Karen Matheson's ties to the island of Barra, they could have fuelled any number of albums simply by trawling through the archives. Instead they've boldly mixed the old with the new, peppering old Scottish waulking (work) songs with contemporary commentaries on politics, both local (Little Do They Know, a tribute to the late Scottish parliamentarian, John Smith) and international (The Boy Who, a tale of Jerusalem street children).

Not subject matter you find readily tucked within a traditional setting, Shaw is insistent that this experimentation and juxtaposing of the new alongside the old is what breathes fresh life into the music.

"I think this album is quite fluid," he suggests, "whereas in the past it may not always have been so. It has been a problem in the past when we were encouraged quite heavily by the record company to write stuff that we weren't all that comfortable with it. But we've steadily written more over the years, and all of the songs on this album were sketches before we started recording.

"So then I made a conscious effort to put them into a form that would feel quite natural for the band to play. And I think that's the secret of using contemporary songs in a 'folk' idiom: you have to have one foot in the 'folkie' camp to make them feel natural within a whole album."

Shaw's involvement with Capercaillie tells only part of his own story.

Working extensively as a producer and guest musician with a swathe of artists, from Karan Casey to Donal Lunny, Dirk Powell and Dan Ar Braz, he's the quintessential renaissance musician who never seems to have to come up for air. In between Capercaillie's recording and touring work, he's heavily occupied with parallel projects.

"It's really hard if you're making music," he acknowledges shyly, "and it's like a drug and you're really getting something out of it - it's really hard to stop. Unfortunately I don't have any yachts to show for it, but I suppose that I've been really lucky to find myself working with some great musicians who I've enjoyed working with, so it's easy to find the energy to make it right. I feel fortunate to be able to do that, to be honest."

And then, there's the film work he's been doing. Shaw makes no apologies for this multi-tasking hyperactivity.

"I've just finished a feature film [One Last Chance, with Dougray Scott, directed by Stuart Svaasand\] last month," he says, "and I found that as we were doing the final mix, I was thinking about the film industry and how it's the ultimate role model for democracy really. You have a director and ultimately the buck stops with him, but all the time he's trying to get out of everybody as much as they can give to achieve the best result.

"I feel that too when I'm writing for film or TV. As much as I enjoy it, trying to do something that's great musically on its own, what's more important is that it works with the picture. It's more about restraint, there's a certain amount of compromise."