Amid shrieks and giggles, the primary 7 class is changing into its national dance costumes (calf-length peasant skirts with rick-rack, and ballet pumps with heels). Among them are three girls who danced in the company's Christmas 1996 production of The Nutcracker. Two of them, Julie Hutchinson from Cambuslang and Sarah McCluskey from Lenzie, started dance lessons when they were barely out of nappies, and Julie now goes to five dance classes a week. Yet, you would go far to meet a more level-headed bunch of 11-year-olds.
"On the first night of The Nutcracker, my mum was more nervous than I was," remembers Julie. "My mum was crying," says Ashley Paterson from Barrhead, who played the part of Clara, the little girl whose dream forms most of the action of the ballet.
Their friends may complain that they can't come out to the cinema, and the boys at school may think it "a load of malarkey", but they are sanguine. "We've got the weekends for cinemas," says Sarah with admirable maturity.
Another girl in the changing room has a professional dancer for a sister. "She tells her what it's like; the bad things like having sore feet every day. " Doesn't that put Sarah off? "No, I think having sore feet every day is what tells you you're a ballet dancer."