SINGING I'M No A Billy, He's A Tim, is one of the most successful theatre shows Scotland has ever seen.
Des Dillon's comedy play, which features a Celtic and a Rangers fan trapped together in a police cell, strips away the bigotry behind the football strips.
But every successful play needs great team players. Brian Beacom talks to actors Tony Kelly, David Alexander and Wullie Brennan, who are currently touring the show to stadium-sized roars of approval.
DAVID Alexander plays Billy. Not only does the 25 year-old have the acting talent to make the role his own, authenticity is guaranteed because David actually played for Rangers.
"I was with the club as a teenager," he recalls.
"I had the club blazer, the lot. But I never made it into the first team.
"I guess I was just a bit too fond of the beer and the kebabs. Later I was offered the chance to go to Hearts, but it was Rangers or nothing."
David's head had also been turned by acting, thanks to drama classes at Stonelaw High in Rutherglen.
"I realised I loved acting and studied at Glasgow's Nautical College," he says.
"Since then I've worked in theatre, and a part in Limmy's Show.
"Then I heard Des was re-casting Billy and Tim and was desperate to get the part.
"Thankfully, I'd seen the play a few times and I studied it, then got in touch with Des. At the time he had picked his cast, but he kept me in mind and when the previous actor landed a film part. Suddenly, I was in."
David was brought up in a Rangers supporting family. "I still go to the games and I know the world. And I've seen the bigotry around me. But I like to think I bring a bit of humour to the part."
Des Dillon realised that David actually looks like Celtic striker Kris Commons. So of course Des wrote this into the script.
"In the play, Tim calls me a 'fat Kris Commons," he says, grinning. "And it happens to be true. I do need to lose a wee bit of weight."
David doesn't regret the missed chance to become a professional footballer.
"No, because I wouldn't be doing this job, which I love, appearing in an incredible play," he says.
"And who knows what this could lead to."
Tony Kelly plays Tim. Growing up in Jordanhill, he was a singer at school and reckoned he would become a pop star.
On the rocky road to fame he appeared on dating quiz show Man O Man, fronted by Chris Tarrant, and it paid off.
Tony was recommended for an audition for a new boy band being created.
After five auditions, Tony was told he had come fifth in the selection process. But the band had only four members.
And the boy band? It was Blue, featuring likes of Duncan James and Lee Ryan who would go on to have huge chart success with songs such as Too Close.
"It took me a while to get over it," Tony recalls with a wry grin. "Afterwards I shaved my hair and got drunk for a few months."
But he came back fighting studying Musical Theatre at Motherwell College and going on to achieve a First Class Honours degree in Acting.
Since then Tony has worked in musical cabaret shows, and now teaches musical theatre and acting classes at Glasgow Acting Academy.
"When I heard Des was putting together a new cast I went to see him, and joined the team," he says.
"It's gone from strength to strength."
Tony, now 34, also knows the Old Firm world. He shared his season ticket with his dad.
"I was brought up with two older brothers in the 80s when the Old Firm rivalry was really at its height. We weren't allowed to wear football strips as a kid.
"We understood the impact of it all."
He's since come to understand the need to work hard to achieve success.
"You have to put the work in. I once used the phrase, 'What's for you won't go by you,' as an excuse not to train and work hard.
"I've realised you can believe in fate, but ultimately you get back what you put in."
Wullie Brennan plays Harry the jailer. The actor from Coatbridge was a joiner before the smell of greasepaint lured him to the stage.
"I think acting is in you or it's not," he says.
"I'd always wanted to sing a song or tell a joke as a kid. But I came into the business really late. "It was only after watching my three daughters grow up I joined am-dram outfit, and that was because I was building sets for the company. But gradually, I took on some small roles."
He then studied acting at Motherwell College, but failed to make it into RSAMD.
"My mother died at the time, and I sort of lost heart so I didn't try again. But for the past 15 years I've worked a lot with Hopscotch Theatre Company."
When Des Dillon wrote the play he had Wullie in mind to play the part of the soft-hearted cop with the tough exterior.
"Des is actually my wife's cousin. Andy Cameron played the role originally on stage but I can understand that. When you produce a new play you want a name in the cast who will get you publicity.
"But when Andy left the show, I took over. And it's been great."
The role of Harry is pivotal; he's the peacekeeper, the voice of reason. And ultimately, he determines the fate of the warring fans.
"I'm not on stage too long so I've got to make sure I get it exactly right. Every time."
Wullie is glad he made the career switch.
"I get lots of phone calls from actors asking if I can fit some cupboards," he says, smiling." But it doesn't interest me.
"I love acting too much."
n Singing I'm No A Billy He's A Tim, the Clyde Auditorium, May 17.