Sixteen P7s from Broomhouse Primary in Edinburgh are seated in a circle at The Hub, the Edinburgh International Festival's base, around California-based actress Joan Macintosh and her colleague Kathleen MacPherson.
Ms Macintosh, who has played numerous major female stage roles, has appeared in the television series The West Wing and has worked with Meryl Streep and Al Pacino, is also a tutor at California's Institute of the Arts. She displays austerity and authority that instils in her young charges a growing confidence about their dramatic ability.
Ms MacPherson asks the youngsters if they know about an energy or force field. "This is your feeling field, which is important when you're on stage acting," she says.
From across the room, class teacher Linda Darroch watches and is impressed by the spatial awareness exercises. The children must imagine they are trees with roots going deep into the ground. Ms Macintosh asks them how that makes them feel. The most popular answer is that it makes their limbs and feet feel heavy.
The children pair up and take it in turns to direct their back to their partner and shout out when they can sense their presence approaching behind them.
Class assistant Shirley Darling says: "That game would work with children with poor spatial awareness. They regularly invade other people's space and that causes confrontation.
"Equally they have no sense of stranger danger. These games would make them consider what it means to feel vulnerable".
EIF programme development manager Sally Hobson says this sort of grounding work makes children more focussed and better able to communicate. "If you listen to children in the playground, some just shout each other down, so you have to get them listening to each other.
"This project is all about subverting the mind. As we get older we have to think more intellectually and lose the ability to work intuitively."
During a snack break before the real improvisation work begins, Ms Macintosh explains how she is trying to adopt energy awareness into her acting classes. This requires expanding our vocabulary to describe what it means to connect with others. "Often acting students do this instinctively but unless you are connecting with the rest of the cast on stage the magic isn't there, so that's why we need to redefine the language," she says.
When given the word, the children rush to the dressing-up rail and put on some unlikely combinations of clothing. This is the basis of the character they name and become. Ms Macintosh mingles among them, suggesting refinements and fixing a feather boa.
The class is split into groups to form four separate bus stop queues. They are directed to join the queue gradually and let conversations and actions develop.
The initial excitement about dressing-up has been replaced by some nerves and self-consciousness. Ms Macintosh directs them with questions such as "What's happening here?" and "What kind of conversation will develop?" She emphasises that the children should not think too much and treats them like serious drama students by calling them actors and making clear distinctions between the auditorium, off stage and on stage.
Ms Macintosh tells them the stage is a magical place and in this exercise they are creating a story from scratch, in the moment. "Just start it and see what happens, like you would a conversation." She urges them to make a strong choice about their identity and throw out their energy.
Each group is given two shots at improvising and on the second run they are more comfortable in their characters and speaking louder.
In one incident, an argument unfolds about a stolen hat. In another, one boy mimes painting the bus stop, to Ms Macintosh's delight.
From experience, Ms Hobson says, the children always respond well to American drama teachers, perhaps because things are more freeform in the American mind than the European.
In all, 400 pupils from 20 Edinburgh schools, including eight secondaries, were involved in the EIF autumn project. "It's a good time to catch them," says Ms Hobson, particularly the secondary schools, "as there's not so much time pressure on them."