Proclaimers' Sunshine on Leith returns to the stage - with added songs

Thankfully, Stephen Greenhorn, who would go on to create the BBC series River City solved the problem, thanks to a night on the sauce, a light bulb moment – and an unpaid gas bill.

And the result was the phenomenally successful Sunshine on Leith, which is now being revived. He rewinds on the demands of 2005. “I had worked with [director] James Brining during his stint at Tag Theatre,” recalls the playwright, “and when he took over at Dundee Rep he said, ‘Wouldn’t it be great if we could do a big, Scottish musical?’

“We thought of finding a composer to write the songs, but it was hard to find a compatible soul. So, we reckoned on using the works of a Scottish band. But they often use many different styles. And the songs just wouldn’t lend themselves to a narrative.”

So, the likes of Simple Minds, for example, or Altered Images, weren’t in the running? “No,” he grins. “And it became clearer we weren’t looking for boy-meets-girl type songs either.”

Greenhorn struggled to find such a back catalogue. Until... “One night I was sitting in my flat in Glasgow, having a few drinks and listening to The Proclaimers' first album. And there’s a track on it The Part That Really Matters, and in the song, they speak, which always makes me laugh when they do it.”

His (slightly?) addled brain screamed out to him that this sounded like a song from a musical. “Then I thought: ‘Oh my, God, these guys have written about everything. About finding love, losing love, being a parent, being a child, politics, community, home . . . I was so excited.”

Yet, given he was also a little tired and emotional, Greenhorn feared the lightbulb would burn out during the night. “To remind myself, I wrote the words ‘Proclaimers' musical’ on the back of my gas bill, and went to bed,” he recalls.

The next morning, the bulb had indeed gone out. But a glance at the missive from Scottish Power brought it all back. And some deep listening to Proclaimers' albums offered up clues about the storyline, which became a tale of two squaddies returning from the Iraq war to their home in Leith. It’s about lost loves, holding together relationships and community, with a searing backdrop of NHS cuts and nods to gentrification.

Two years later the show launched in Dundee, and it coincided with the Proclaimers having a Number One hit, I’m Gonna Be (500 Miles). Then came the film, which attracted a younger demographic and very good reviews.

But was there ever a chance the film producers would look to an established screenwriter and the Sunshine boy would be side-lined? “Well, when you sell the rights to turn the musical into a film you then have to apply for the job of writing the screenplay. And the contract says if the producers don’t like the script you turn in, they can fire you and bring someone else in.”

A wry smile suggests he was concerned. “Theatre considers writers as having an honoured place. But the film world isn’t known for its collegiate, friendly qualities. It’s all about the director. Thankfully Dexter Fletcher liked what I was trying to do.”

He offers a dark smile. “I don’t know how I would have coped had I not been given the chance to write the film.”

Back to the theatre show. Sunshine is his baby, and he reveals this new production sees the baby wearing a nice, less expensive but very smart-looking outfit. “Yes, we wanted to revamp it, to make it tighter, more focused than ever. So, we moved away from the large cast and the large number of musicians because the overheads had become too great.

“Now, we have more actor/musicians, reducing the cost. And we’ve got more Proclaimers' songs being thread, so it’s more scored than the previous production.”

Sunshine is one of many Stephen Greenhorn success stories. His classic play Passing Places became a feature of the Scottish Higher syllabus. He has also written extensively for television, with the likes of Dr Who, and more recently Around the World in 80 Days, starring David Tennant.

But was writing always part of his very being? Past interviews reveal he grew up in Fauldhouse in West Lothian, studied Physics at Heriot Watt before switching to Strathclyde University where his English Lit degree included a life-changing Theatre Studies option.

For the practical part, he wrote a play, Heart and Bone, which won him a Fringe First. He loved this new world. Yet, surely there must have been a lurking need to batter a typewriter? “Well, yes,” he admits, smiling. “Thinking back now, I was one of those kids who was consumed by stories. If you ask any of my family they’ll remember me with my snorkel parka in the house, fully zipped up while watching the television, or in the corner reading a book, with everyone else excluded. Or I’d be in Fauldhouse library consuming the kids’ stuff, and then stealing my mum’s ticket to raid the adult stuff.

“Growing up in a little mining village in West Lothian you were left with the sense that stories were great, but they happened somewhere else. It was only really watching the likes of 7:84 Theatre Company and Bill Forsyth films that I realised stories could come out of Scotland.”

He laughs: “But it took a long time to go from being the boy with the parka absorbing other stories to thinking that maybe I could write them.”

Sunshine, with its perfect musical accompaniment connects wonderfully with its audiences. Although it’s Scottish, rooted in Edinburgh, the show’s themes are universal. “Those songs travel. They have a truth about them, and that truth will always travel.”

Further than he could ever imagine? “It actually went on in Mumbai,” he says in delighted voice. “I could never have predicted that one.”

Sunshine On Leith, the King’s Theatre, Edinburgh, June 7-18, Pitlochry Festival Theatre, May 20-October 1.