When the core members got together to record the Roses And Tears album in 2008, the feeling was, says singer Karen Matheson, that they should lay the band to rest, release the album, do some dates to promote it and say goodbye to their fans.
"Then we went out on the road and had such a hoot," says Matheson, the owner of a voice that Sean Connery famously described as having been "surely touched by the hand of God". "We thought, if we can have this much fun, why stop? Because going out and having a craic with music is what it's all about. Did we ever think when we started out that we'd be doing this for 30 years? No, but I'm really glad we have."
In the beginning, of course, there was no Matheson in the band. In fact, there was no band. Donald Shaw, at the time a teenage accordionist with a passion for traditional music, and three of his friends landed an invitation to play a pub session at Mull Music Festival.
They so impressed a chap from the BBC that he came up to them afterwards and asked what their band was called. To which Shaw replied that they weren't actually a band.
Unperturbed, the BBC man suggested that they should record a session for radio adding that they should bring a singer with them. They didn't have a singer but Shaw knew someone in his village - Taynuilt, near Oban - who could sing. And so with the first Hebridean sean-nos - or old style-Gaelic song - to be accompanied by the then state-of-the-art Prophet 5 synthesiser, which Shaw's musician father had driven him down to Edinburgh to buy, Matheson's voice hit the airwaves for the first of innumerable times.
Matheson is the first to admit that she wasn't a natural performer. She was shy as a child (it took her years to learn how to relax on stage with the band, she says) and although her grandmother, who lived with the family in Taynuilt, used to teach her songs, she was very reluctant to sing them in public.
"My mum came from Barra and she'd gone through the thing of coming to the mainland and being shunned as a Gaelic speaker. So she was always a bit anti-Gaelic," says Matheson. "She'd say, don't bother learning Gaelic, it'll get you nowhere. But my dad, on the other hand, he was from Skye and he played accordion, and every time there was a ceilidh on in the village, which would usually be at Donald's parents' house, he'd take me along. He'd be encouraging me to sing and I'd be hiding behind the couch."
Between her grandmother's songs and the efforts of her primary school teacher, who encouraged all her pupils to sing Gaelic songs or recite poetry if they genuinely couldn't sing, and to whom Matheson says she owes everything, the future singer in Capercaillie began to accumulate a repertoire.
"Although I didn't grow up speaking Gaelic, I lived and breathed the culture, as did Donald, who was always very passionate about it, so it was natural for us to want to play and sing Gaelic music," she says. "At the time, what people outside of the Highlands and Islands heard of Gaelic would be very formal. The traditional singers, like Flora MacNeil, Ishbel MacAskill and Mary Smith, who were my main influences, along with Anne Lorne Gillies, weren't being heard widely the way Gaelic singers are now. There were also more innovative things happening in Ireland and Donald, who was very much influenced by the Irish scene, felt that we should be trying to make traditional music more contemporary over here."
Capercaillie's early albums stayed largely true to the acoustic tradition but, with instruments like the aforementioned synthesiser and bass guitar adding colour and punch. As their sound caught on, they began to travel and gather a following, making inroads into the US, where the music of Scotland and Ireland finds a ready market among the diaspora.
It was upon returning from one American tour in the early 1990s that they realised just how far they'd come here at home in terms of building an audience. The late, much-missed Glasgow promoter Billy Kelly, who had Gaelic leanings due to his wife's background, had championed Capercaillie early on and before they'd set off for the States he'd promised them a gig at the annual Mayfest celebration, whose music strand Kelly presided over with an expert's ear.
"We came back from that American tour to find that we were playing the City Hall in Glasgow and that, to our amazement, it had sold out," says Matheson. "That was definitely a turning point because I don't think we'd ever imagined that we'd be playing to that size of audience."
Subsequent Mayfests would see them move further up the scale to the Pavilion and catching performers including the Beninoise singer Angelique Kidjo, whose Glasgow Green concert Matheson remembers as pointing the way for taking indigenous music into the contemporary arena.
Another turning point was when their EP, A Prince Among Islands, with its radio-friendly track Coisich A Ruin, became the first Gaelic record to reach the UK Top 40 in 1992.
Matheson remembers not just hearing the song on Radio 1 and Radio 2 but shortly afterwards having, for the time, the most unlikely experience for folk musicians of being asked to dress in designer clothing for photo shoots. It was also suggested that the band should move to Ireland as that would be better for their image but, their Donegal-based bouzouki player Manus Lunny aside, they decided to stick with Scotland, where other doors, such as the popular television series Transatlantic Sessions, were opening for Matheson and Shaw particularly.
"Everybody in the band has always had other projects on the go," says Matheson, "and they feed into Capercaillie. I think that's helped us to keep developing. We have to keep ourselves interested and excited by what we're doing, otherwise there would be no point in trying to interest an audience. I think travelling around the world and having people from around the world bringing their music to festivals like Celtic Connections has definitely stimulated us too."
Shaw's involvement as director of Celtic Connections has certainly played a part in exposing his fellow musicians in Capercaillie - Manus Lunny, fiddler Charlie McKerron, flautist Michael McGoldrick and bassist Ewen Vernal - to an international cast of players, often through direct collaborations. But he and Matheson are also very much aware of what's happening on the wider Scottish traditional music scene, which Matheson says has never been more exciting.
"It's not just the volume of young players and singers who are coming through," she says. "It's the quality, too. The Fèisean movement has done a fantastic job in teaching young people how to play their own traditional music and the standard of students who are coming out of the Royal Conservatoire of Music's Scottish music course is phenomenal. The standard here now is on a par with any music worldwide."
It was in recognition of this that guests such as Julie Fowlis, Kathleen MacInnes, Darren Maclean and Kris Drever, who are some of the people Matheson cites as being at the Scottish tradition's leading edge, were invited to participate on Capercaillie's 30th anniversary release, At The Heart Of It All. The album was worked up in the band's old way, getting together in Matheson and Shaw's front room with a bottle of wine and a few ideas, then taking the music into the studio and trying to get as live a feel as possible.
"You never get the spontaneity of a live gig in the studio but it's fun trying," she says. "The great thing about this music, though, is that you never run out of songs and the supply's become more readily available with Tobar an Dualchais, the kist of riches that gives internet access to the School of Scottish Studies' traditional music resources.
"I remember when we started, you'd have to book time at the library at Edinburgh University and you couldn't take anything away with you. Now you can hear thousands of songs at the press of button. I wish we'd had that 30 years ago."
At The Heart Of It All is out now on Vertical Records. Capercaillie play Usher Hall, Edinburgh on November 10, Aberdeen Music Hall on November 12 and Perth Concert Hall on November 13