THE members range from a procurator fiscal and a heritage manager to taxi drivers, tradesmen and even a 75-year-old pensioner.
But when this collection of unlikely performers come together, something works.
It works so well in fact that the amateur Sing in the City group has already sold out two 500-ticket gigs at Pilrig St Paul's and the George Square Lecture Theatre - and is now set to record a CD.
After just ten months, the group is scouting out city theatres ahead of its first Festival run.
Kirsty Baird, 43, director of Sing in the City, said it started out as a small council singing group but soon branched out into a more ambitious project.
"It wasn't my intention to be doing concerts with 500 people in the audience within two years, let alone within a few months, it just kind of happened and everyone got good," she said. "We started with a handful of members and now we've got 70.
"It's a bit like a Mexican wave, a few people started and then everyone wanted to join in. They've got such passion."
Kirsty, who works professionally as a singer and musician, also runs Kids Rock UK and is considering setting up a choir for youngsters as well.
She has already been approached by British Gas and Maggie's Cancer Care for events. The proceeds of the group's CD, which they begin recording on March 12, will go to Maggie's.
She said: "We've got every profession you could need. If we ever need any jobs done we'll have it in the choir. We've got a procurator fiscal, PR people, we've got grandmothers, students, taxi drivers, plumbers, joiners. I think I'll never have to pick up the Yellow Pages again."
Among the choir's recent recruits is heritage manager Neil Gregory, 37, who had friends in the group and ended up joining after seeing them on stage.
He said: "Before joining the choir it must have been 25 years since I'd sung anything. I dropped my guard at a karaoke night and my friends roped me into it after hearing me do Shakin' Stevens.
"Some of the tunes we do at Sing in the City you wouldn't dream of having in your record collection, but they sound great on stage and are so much fun to perform.
"People always think I've joined because of that show Glee.
"I think it's a dreadful programme, but there's a good chance it's due to that that we've had such a great response at our concerts."
Speaking about this summer's Festival, Kirsty added: "I want them to experience the Festival.I think running around the Royal Mile with a 70- person choir will be hilarious.
"I'm really struggling to find a place that's big enough, but not the Playhouse, because we're not quite there yet."