ON a hot afternoon towards the end of June, the Cuillin ridge zigzagging above Skye like God’s own ECG, Donnie Munro stops outside his childhood home: a roughcast semi on Kitson Crescent, Portree, and points to what had been his bedroom window. “I always said,” he says, “that this must be the best view from any council house in Britain.”

Picture him in the summer of 1973, aged nineteen, on the other side of the glass. Looking out, he would have seen Ben Tianavaig and, beyond, Raasay. What he could not have seen, nor imagined, was a future in which Runrig, the band for which he had just started to sing, would become the biggest in Scotland and have a lasting impact on Scottish culture. But the ingredients of that success were all around. Malcolm Jones – later the guitarist, but then still at school – lived down the street. The brothers Rory and Calum Macdonald, Runrig’s songwriting partnership, were on Fraser Crescent, around the corner; so close that on summer nights, windows open to the island air, they could hear the fledgling rock star singing into the bathroom mirror, giving Elvis laldy.

“There was a dance every night in different villages around the island,” Munro recalls. “We were playing five, six nights a week.” Those drouthy whisky evenings at the Skye Gathering Hall, the Portree British Legion, Kyleakin Badminton Club were Runrig’s equivalent of the Beatles in Hamburg; playing Proud Mary and Gay Gordons, learning their trade, earning their stripes. Never on a Sunday, of course; the peace of the Sabbath was observed, a policy Runrig have maintained throughout a 45-year career which, soon now, will come to an end.

If Donnie Munro is in nostalgic mood, it is to a purpose. Having left Runrig in 1997 (to be replaced by the Canadian singer Bruce Guthro) he will be reunited with the band at the Last Dance, two farewell concerts in Stirling in August, in front of 45,000 fans. “Runrig is a hard thing to let go,” Calum Macdonald had told me when we met at his home in the Highlands. “It has been our life’s work, so there’s an emotional attachment. It was a difficult decision, but deep within us we know it is the right one. Let’s have a clean end and be positive about it. Bring the ship home to a safe harbour.”

Driving around Scotland, meeting Runrig members past and present, there is time to listen deeply to their body of work, from 1978’s Play Gaelic through their 1987 smash The Cutter And The Clan (at the time, the fastest-selling LP ever released in Scotland) to their elegiac final album The Story. Their catalogue is sophisticated, complex, engaged with people, place, identity, faith. Little wonder their frustration at being pigeonholed as kitschy professional Scots. “Our records still get put in the racks with the Scottish dance bands and pipe bands rather than between Run-DMC and the Rolling Stones where they should be,” Calum sighed. “The national thing, it overwhelms you.”

Here is a band whose contribution to Scottish culture has been immense, even historic. Their true place is among a lineage that stretches through Robert Burns, Billy Connolly and the historian John Prebble; their internationally popular stories of Scotland and Scottishness have, arguably, had a shaping influence on the way we see ourselves and are seen by the world. In particular, as the first band to fuse the Gaelic language with rock, they remade an ancient tradition for a new age.

“They changed the face of music with their compositions in Gaelic,” says Julie Fowlis. The 39-year-old singer-songwriter grew up with Runrig, as did many Hebrideans of her generation; as a schoolgirl in North Uist, in 1990, she appeared in a video for the song Siol Ghoraidh. “Theirs was an entirely new voice. It was brave and bold and from the heart. They took the language with them and kept it with them on their journey. We owe them a lot.”

An old accordion. An older photograph. If the story of Runrig could be told in two objects, it would be these. Each has a totemic power.

“It’s a defining image of where I came from. A very peasant-looking photo,” Calum Macdonald explained. “I found it in a drawer in our house in Skye. It’s my grandmother and her friends round about.” Black and white, torn in one corner, the picture shows a group of islanders stooking corn in the 1930s. He found it in 1975, in his early twenties, and it became a “personal talisman”, inspiring the sort of songs he would go on to write; rooted in the land, the language, personal and cultural history.

The Uist novelist Angus Peter Campbell has described the impact on the Hebrides of Runrig’s success: “By becoming international stars they have made the local universal and continue to give dignity to a scorned people and a scorned culture.”

Is that how Calum saw it? That when they were on stage, or in the studio, they were representing not only themselves, but their folk? “Yes, absolutely. We were very aware of carrying that with us, and proud to do it.”

Wasn’t it a burden? “No, an absolute privilege. But it was crucial that we weren’t doing it as a pressure group, or a political movement in any way, because that would weaken it. It had to be done naturally.”

Rory Macdonald is 69, his brother’s senior by almost five years. Calum is Runrig’s chief lyricist, Rory, who plays bass, is the driving musical force. We spoke at his home on the Dornoch Firth before taking a turn on the sand. He seemed in good humour, even when asked about Loch Lomond. The band’s best known song, it has likely contributed a great deal to the perception of Runrig as couthy and sentimental. But no, he said, there were no regrets about covering it. “Except at weddings, quite often it’s the last song of the night. That’s my cue to go to the toilet. It’s not cool to dance to your own record.”

Talk turned to his late father. Donald John Macdonald had served with the Argyll and Sutherland Highlanders during the Second World War, later joining the police, before becoming a social worker. One of Runrig’s most beautiful songs, An Ubhal as Àirde, is about him. It became the first Gaelic song to make it into the UK top 20.

“He was a gregarious character, the life and soul, but like most of his generation he tried to shield what he’d experienced during the war,” Rory said. "There was pain. He saw his friend killed. He was standing in the turret of the tank, and thought he’d been shot because he was suddenly covered in blood. But it wasn’t his. His best pal died beside him.”

This was Sandy MacIntyre. The tank crew had been ambushed in Normandy. Donald John, a sergeant, wrote to his friend’s parents to inform them of their loss, and kept in touch.

“I remember going with my dad to visit Sandy’s folks in Greenock, when I was about nine,” Rory recalled. “They were obviously poor, and just really nice people. A little kitchen-living room; all the washing hanging off a pulley. Just as we were leaving, his mum said, ‘Well, Sandy’s accordion’s still here, and we’d like to give it to your boy.’ They brought it down, in a black case, and gave it to me.”

A beautful blue Hohner, here was a treasure and a passed torch. Keys that should have been pressed by their son, and perhaps his child in turn, would yield music under the fingers of Rory instead. Later, he would play it on the anti-war song The Everlasting Gun, but its greater significance is that it was his first instrument, setting him down the path to Runrig.

“That was massive,” he nodded. “One of those moments in life that are key and that you always remember. I was aware not just of getting the accordion, but the love and kindness behind that.”

Blood, then, watered the roots of Runrig. Blood spilled in France, blood passed between generations in the Hebrides. A sense of the tragic and a sense of tradition, both at the heart of the band’s music, symbolised by that family photograph found in a drawer, that instrument which found a new life.

Runrig’s pretty melodies sometimes come spiked with venom. The Everlasting Gun is one hell of an angry song. Perhaps because of the language barrier, it is little understood how important an emotion anger is in the band’s work. They are seen by many as soft-focus, shortbread-tin; all kilt, no dirk. Listen, though, to Tir An Airm (a protest song against military bases) or Dance Called America (a rage against the Highland Clearances) or especially Fichead Bliadhna, which expresses Calum Macdonald’s frustration that he and his generation were taught nothing at school of the Clearances and other traumas of Gaeldom.

Although they have a politics, the band has, generally, avoided making statements of support for any one party. Internally, though, there has been discussion. “For most rock bands, it was sex, drugs and rock ’n’ roll at the back of the tour bus, but Runrig were too busy debating Scotland’s constitutional question,” said Pete Wishart, the band’s keyboard player from 1986 and 2001.

In common with the rest of the band, Wishart came from a Labour-supporting background, but his immersion in Runrig made him better understand and sympathise with issues, such as land ownership, which were part of the devolution agenda. “I’m not saying I’m a nationalist, and I probably never will join the SNP,” was his view in a 1991 interview. He is now the SNP MP for Perth and North Perthshire.

His political journey, he feels, is typical of Runrig’s influence on Scotland: a hugely popular band which seemed to foreground and explore Scottish identity, they were part of a wave of cultural nationalism which, quite without intent, seeded the ground for political nationalism.

“I always felt that Runrig were the soundtrack to the emerging of the Scottish Parliament,” Wishart told me. “Our song Alba is essentially about that. It was no longer unfashionable to raise issues to do with the Gaelic culture or language. Scotland was learning to love and appreciate a sense of itself as confident and assertive. All the other political changes could never have happened without a feeling that what we have in Scotland is important and worth celebrating.”

Tensions within the group arose not as a result of differences in ideology, but rather over the question of whether band members should be open about their party allegiances. Rory, in particular, was appalled by Donnie Munro’s decision, in the early 1990s, to declare his support for Labour: “I didn’t want the music to be tainted by propaganda, or for a political party to be feeding off the name of the band. That hurt a wee bit.”

Munro’s decision to leave the band hit Rory hard. “I was devastated. It was almost like the break-up of a love affair, and for quite a while after that there was a frostiness. That’s human nature. But we’re grand now.”

A long audition process was required to find a replacement: Bruce Guthro, a singer-songwriter from Nova Scotia. “The moment we heard him singing it felt right,” Calum explained. “But he also came with a story.” Emigration to Canada – that sense of exile and homesick yearning – had long been a Runrig theme. “So it was like we were taking something back from the diaspora. That was exciting.”

It has become an accepted narrative that Munro left the band for politics, standing in the 1997 general election for the seat of Ross, Skye and Inverness West, and losing to Charles Kennedy. When we meet, he explains that it wasn’t quite that simple. He also missed his wife and children while on tour, and wondered how much more, creatively, he had to offer. “But I think, though I ceased to perform with Runrig, in my head I never really really left the band. I’ve never been able nor wanted to separate myself from what we did collectively.”

Munro is director of development, fundraising and the arts at Sabhal Mòr Ostaig, the Gaelic college on Skye; it was established in 1973, the same year as Runrig, and Munro sees his work as an extension of what the band was doing – expressing ideas, being part of the regeneration of culture and community. At the farewell concerts, he will perform a couple of songs with the band, but will also open the show with a set which will include Runrig material.

“I would have felt very disconnected not to have participated in the last shows,” he says. “It’s such a momentous thing for all us in lots of ways. It’s an opportunity to celebrate the connection with this audience. For many people, it’s not just a concert, it’s a piece of their personal history.”

Lea Andrews will be there in Stirling, on the final night. How could she not be? For the 32 year old fan from Gateshead, the Last Dance is a last chance to express through her presence gratitude for what the band has meant all these years. Her parents split up when she was two; her father had custody, but she wanted to live with her mother. Her stepfather and mother became fans of Runrig after seeing them live in Portree, and introduced the little girl to their music.

“Because I was pining after me mam so much, their music became synonymous with the feeling I had when I was with her,” Lea recalls. She saw her mother every second weekend; between times, on a Walkman, she would listen to Runrig. Every River, City of Lights, Always The Winner – these songs became both the soundtrack to separation, and lullabies containing the promise of reunion. “The sound of Donnie’s voice gave me such huge comfort, and that comfort has lasted throughout my life.”

Could it have been any band that made Lea, as a child, feel soothed and understood? Was it just a fluke that it turned out to be Runrig? Arguably not. The music of Calum and Rory Macdonald, which so often touches on ideas of homesickness and homecoming, emerges from their childhood experience of separation.

“A significant moment in our lives was when we left Uist and flitted to Skye,” Rory recalled. He was 12 years old that summer, his brother seven. Their father had a new job on the much larger island. “My dad hired a small cargo boat from Scalpay. At about seven o’ clock that evening, we were all set to leave, and most of the village came down to see us off. As the boat was pulling away, all these people were on the pier waving to us. That experience is ingrained in Calum and I, and it has triggered a lot of songs.”

Rory seemed moved by the recollection. When you close your eyes, I asked, can you see it? “I can see it and feel it. It was visceral, hugely emotional. It gets you in the gut.”

For people who don’t come from that island culture, this strength of feeling might be difficult to understand. After all, it’s not as if the family was leaving for a new life in America; yet the Minch can be an Atlantic of the mind. “You were leaving a community that had enveloped you,” Rory explained. “One where you knew everybody. You were aware of the love that was being imparted by these people coming down to the pier. All your friends. It was just overwhelming.”

Would it be reasonable to suggest that the Macdonald brothers’ later empathy for those forced from their homes during the Clearances, and their ability to articulate that pain in song, goes back to this early experience of being uprooted? “Yes, we could identify with all that. It was a very intense experience.”

In his foreword to Flower Of The West: The Runrig Songbook, the poet Aonghas MacNeacail notes that the Macdonalds grew up under the influence of two elemental landscapes: sea-scaped Uist and mountainous Skye; the former, it could be argued, gives their music its melancholy, the latter its grandeur. Other early influences included the left-wing radicalism of the West Highland Free Press, the newspaper founded in Skye the year before Runrig formed, and the psalm-singing of the Free Presbyterian Church in which the Macdonalds were raised. One might also mention a gentleman known as Willie the Barber, whose shop by the pier in Portree doubled as the village’s record store; as the 1960s worn on, the nascent rockers of Skye, chary of scissors, became more likely to visit the barber for the ecstatic records they were hearing on Radio Luxembourg. When Rory Macdonald heard Procul Harum’s Whiter Shade Of Pale for the first time, he rose from the family dinner table and went up, weeping, to his room.

The sea, the psalms, and socialism; hard rock and soft island skies – all of these are part of Runrig, and Runrig is, forevermore, part of Scotland’s story. Only the Stirling concerts remain. On that final night, as they play each song, they will know it is for the last time. Alba no more. Skye no more. Loch Lomond no more.

“It’s going to be hard,” Rory said. “I do just occasionally think, ‘Are we doing the right thing?’ But no, I’m at peace with it. I hope the concerts will be celebratory. Maybe, at the end, a few tears will be shed …”

Runrig: The Last Dance will be at City Park, Stirling, on August 17 & 18