It’s arguably the most famous rivalry in world sport and a subject that can arouse strong opinions – even among non-football fans.
Supporters of Rangers and Celtic will tell you there are many reasons – some even based on fact – why these two Glasgow clubs love to loathe each other.
So you would be forgiven for being surprised this rivalry is the basis of a critically acclaimed comedy.
‘Singin’ I’m no Billy, He’s a Tim’ takes a light-hearted look at the supposed differences between Rangers and Celtic fans and concludes they have a lot more in common than they sometimes like to think.
Written by Des Dillon, the play has packed theatres across Scotland since it was first performed at the Edinburgh Fringe in 2005.
The story follows a Rangers and a Celtic fan locked up together in a police station cell for the duration of an Old Firm match.
It will be staged at Grangemouth Town Hall on Friday, July 26, as part of the fourth Funny in Falkirk festival.
The Falkirk Herald spoke to actor David Alexander, one of the two leads, about this most unlikely of comedies.
“It doesn’t matter where we go, the show always gets a very positive response from the audience. There’s never any trouble,” he said. “We often get people saying, ‘aye, I often say things like that’.
David (25), from Glasgow, said the play’s central message is a simple one. “The two fans are forced to coexist. They slowly realise they have a lot in common, and perhaps there really is more to life than football.”