So, if the citizens of Glasgow only saw young people from the other parts of Europe lying down in Kelvingrove Park and throwing bags of flour at one another on Garnethill, then they would have been merely looking through a glass darkly. To get an idea of the flavour of the event, they needed to feel it.
"It's the feeling of the space around you, the intimate feel of yourself responding to the city," says Kasha, who is visiting from the Anglican International School in Jerusalem and wants to be a jazz pianist and sculptor. She lay down with two others on the park pathway "to change the way people saw Glasgow that morning, to let people choose how to relate to her art".
Kasha is one of 50 students from British and American schools in Israel, Turkey and Portugal who came to Glasgow last weekend to share a theatre school with the same number of students from the RSAMD's Junior Academy of Drama, the Scottish Youth Theatre and the Academy of Musical Theatre Arts.
The International Schools Theatre Association holds several of these festivals each year, in different parts of the world, to extend the theatre education and internationalism of their pupils. What is different about this one is that for the first time the host organisation partners the visitors with local people, both as colleagues and leaders. The latter are the second year students of the contemporary theatre practice course at the RSAMD, and they have led the local students in six weeks of preparation as part of their "theatre in educational contexts" module.
"We had to look at Glasgow as a performance space," explains Helen Batchelor. "Straight away, it was obvious the local kids had never really looked at the city. Then we had to pare away their concept of what theatre is and what it needs, all the time allowing them to learn implicitly."
What they learn is to dissolve the boundaries between art and non-art. So they make theatre as they walk along Renfrew Street, without narrative, character or dialogue. Or they find a venue that suggests a dramatic event.
Claremont Pass is a short lane, with railings on each side.
Surreally, arms reach out, pleading or begging to be touched. Then the passer-by is gripped, and mugged by the converging gang, and propped against the railings. No residents, it must be said, are harmed in the making of this performance art.
In the park, we see figures that gently blend with the landscape and encounter others that grate on the pastoral calm, the irritable old man who sits all day refusing to speak, the gossipy woman and the young couple who only argue and fight.
In the end, everyone gathers in front of the splendid but derelict fountain, sings a song of home and dances the locally popular linedance "The Slosh".
"Anyone who sees this will have their day changed," says Jess Thorpe, a Glasgow-based performance artist who is directing the project. "They will remember the cold morning they saw people dancing in the park. They will go home and tell their family. It will, in a small way, have changed their world."
A recent graduate of the contemporary theatre practice course, Thorpe admits to having found the prospect "quite daunting" but her relief and pleasure at the performances is evident.
"It's brilliant to watch the interchanges taking place and seeing them make friends," she says, "But best of all, everything they do seems real."
It is a surprising remark, perhaps, but it goes to the core of the weekend, which was all about the organic honesty and sincerity of the students'
involvement, and nothing to do with recreating old models. New wine in new bottles, in fact.