It’s the one song that everyone seems to know the lyrics to, it’s the one song, no matter how old you are will know. 500 Miles from the album Sunshine on Leith has a life of it’s own says Charlie Reid from The Proclaimers. It was the song that changed their career and now it’s is one of the most iconic records listened to by millions.

“We thought it may be some sort of minor hit,” admits Charlie when they first recorded the song.

“We actually started playing the song live before we recorded it. It was written around 1987 and in January 1988 we started doing a lot of shows - at the time it was just Craig and I doing an acoustic duo tour. When we did the song it went down quite well, so we recorded it with Pete Wingfield and the band he put together for us.

“We thought that would be the first song off the album that would go to radio. The truth is the record has got more popular with every decade, it’s gone past what we’d imagine. You probably hear the record more now than when it was first released.

“It changed everything. We had a hit single before that with Letter from America and we had a couple of songs later on that did okay, but nothing ever as big as that. It keeps us on the road.”

Speaking about the inspiration behind the song, the 54-year-old, says it was mostly written by his identical twin Craig but they produced it together. “He said it was about his wife... well girlfriend at the time. It is one of those songs people, if they have a strong relationship, it appeals to them.”

The brothers, who moved from their home town Auchtermuchty, Fife to Edinburgh when they were 17, to try and make it on their own, say they had six years of nothing happening and it really is a tough industry to crack.

“We are each others support network,” adds Craig, “as most brothers do, we scraped a bit when we were growing up. But we’re probably more co-operative in that we always stood up for each other…. So when it came to doing what we do for a living we knew what we wanted to do.

“I think we have a very close connection… nothing spooky or anything, we just have that probably same kind of feeling about people. Our likes and dislikes are pretty similar too and we definitely get a vibe off people that we don’t have to explain to each other.”

“We started making songs when we were 15 or 16 and moved away from home to try and make our way. Sometimes the enthusiasm was there and sometimes it waned a little.

"It was tough and you know you are going to get rejected a lot. You get rejected a lot even when you do sign – not everyone is going to be a fan”

To get by, the father of three says they had the odd job here and there.

"It was that time in the early '80s in Scotland and there weren’t many jobs… we had the odd job here and there, but not an awful lot of things. I got some sort of job, it was labouring on a building site, it was government thing and you got the basic same wage every week.

“And then suddenly we got this phone call from someone who had heard the Housemartins band on Radio 1 that had mentioned us and had been trying to contact us. It was just one of those things.

“So we got in contact with them, went to Hull, and then went on tour for about six or seven weeks in Britain and Ireland and that’s what really got us. We met our manager around about the same time and it all just went from there.”

The pair who have been in the industry now for more than 30 years say that the secret to a long, successful career has been being on the road, doing a lot of shows and festivals.

“We've never done it to be famous, we did it because we wanted to express ourselves. I mean there is nothing wrong with fame, but you’re in trouble if you take it too seriously,” explains Charlie.

Remembering their time on tour in America, he tells me: “I think most bands who have toured a lot have had that, PAs not working or in our case the monitor guy slumped over his desk and not monitoring… I won’t mention where the gig was other than in America, but he was obviously smoking something. We didn’t think we would recover from it and you put it down to experience.

“We were also touring in America during 9/11. And for over a month in when it happened, the attendances were down to about 100/ 120 people. It was a bit depressing but of course nobody wanted to travel, everyone was a bit concerned. We’ve toured in good times and bad times.

“But no concert is ever exactly the same,” adds the once Buzzcocks and The Clash fan. “We always try and change things up - there are of course some songs we have to play and audiences expect, but we do vary it as we are so often on the road.”

The Proclaimers will be at Watford Colosseum on Friday, May 20. Details: 01923 571102, watfordcolosseum.co.uk