In a rehearsal room in North London an excitable bunch of playwrights are messing around with a stairlift — until an actor from one of their plays firmly suggests that they leave the equipment alone and play more quietly. The actor, Neil Edmond, already knows that these writers are something special. After all, he’s had to face some pretty tough questions from them at his audition. “They asked me: ‘How good are you out of ten?’ I said: ‘Nine.’ They said, ‘Are you proper loud?’ I said that I was.”

Edmond is one of 20 performers appearing in Jumping for Joy, the latest set of ten short plays produced by Scene & Heard. And, as the observant reader will have spotted by now, Scene & Heard is not your average theatre company. Its founders, Sophie Boyack and Kate Coleman, and its artistic director, Roz Paul, spend their time getting children from Somers Town, a deprived, immigrant-heavy area between King’s Cross and Camden Town, to write plays. And, more unusually, getting professional actors to perform them. For four nights. To real audiences. Free. Each child’s eight-minute drama gets the attention of a script editor, a director and two actors. “This is a mentoring project on a grand scale,” says the ebullient Coleman, who set up the company in 1999 after working with a similar outfit in New York, the 52nd Street Project. “One-on-one? Pah!”

But it’s not just worthiness that has brought the company celebrity supporters such as Damian Lewis, Emily Watson, Michael Sheen, Bill Nighy and Samuel West. It’s entertainment value too. “Scene & Heard is the most fun I’ve ever had in a theatre,” insists West, who reckons he has seen 25 of their shows. “I’m not kidding. It’s simply joyous.” The comedian Neil Mullarkey was so taken with what he saw that he got Coleman to direct one of his own shows. “It’s much better writing than actors normally get,” he says. Oh, come now. “I’m serious. There’s always some little truth about relationships, about how we are, the ins and outs of life, that are so much more stark when you’re nine years old.”

Well-meaning hyperbole? Actually, after spending last Saturday afternoon at a rehearsal, I’m forced to join the cheerleading squad. In a Camden community centre, child playwrights aged 9 to 11 sat watching their work being performed for the first time. And I sat there moved to laughter and even the odd tear by bizarre yet beautiful playlets that keep on cutting to the dramatic chase. Animals and inanimate objects are the protagonists, but get over that device and you’ll find characters who are full of refreshingly straightforward human emotions. The writing is about love, loss, family and aspiration.

The kids are asked to write about objects and animals, Coleman says, to stop them just writing about what they know. To make sure they use their imaginations, rather than just relocating EastEnders to Somers Town. “Once you steer the kids away from celebrity and money,” West says, “you find all the same preoccupations: the need to know where your parents are, a need for reciprocity, for fairness.” Once a script is done, the actors aren’t allowed to change a word, however wonky the grammar.

So, yes, there’s a lot of naivety on display. But that naivety is funny rather than laughable. It catches you by surprise. It reminds you of another way of seeing things. Isn’t that what theatre is all about? Who wouldn’t root for the water pistol in Suban Abdirahman’s play, whose ambition is “to be a normal proper gun that kills people in the Army”? These stories work because the kids are encouraged to see things from their characters’ point of view. And because the adult actors play them without an atom of condescension. “You have to play it absolutely for real,” West says. “If you play it like you’re in something written by a child, you’re going down.”

The kids who attend are nominated by their schools. They tend to have behavioural or educational problems. Getting them to turn up can be difficult. Osman Jalloh, 9, has been to the theatre only once. You’d never guess that from seeing his play. Did he enjoy watching it? “A lot of it was embarrassing,” he shrugs, “some of the things in there I really want to change.” Wow, this one’s a fast learner — give him a year and he’ll be wearing corduroy jackets and publicly berating the Arts Council.

Talking of whom — the company relies on charitable grants and private donations. Getting local council or government money has proved tricky, because what they do is so labour-intensive. “Somebody said to me,” Coleman says, “that for the money it costs you to run a course for ten children, I could get 200 children into a theatre workshop. And I say, yeah, but what’s the impact on those children?”

Performing in public, for an audience of middle-class theatregoers, is a unique form of validation. “It’s about being taken seriously by grown-ups,” Mullarkey says, “and achieving success.”

Jumping for Joy is at Theatre Technis, London NW1 (020-7388 9008; www.sceneandheard.org) from Thur to Sun. Tickets are free but must be reserved in advance

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