Mixed Up North, Wilton's Music Hall, London

Lamda, arguably the most enlightened and inclusive of all London's drama schools, has a highly creative component in its third-year acting course.

An established dramatist comes in and works with these budding thespians on a play that is instigated in the style of Joint Stock, the Seventies company run by Max Stafford-Clark that helped Caryl Churchill on her way to classic status. That's to say, the students go out into the world to research an agreed subject and bring back material that the author then shapes into a finished piece.

This would seem a rather intramural activity, were it not for the fact that the plays so fashioned have a habit of proceeding to full professional production. To cite two examples from recent years, there is Mark Ravenhill's Mother Clap's Molly House about a gay brothel and Di Trevis's extraordinary bid to make a theatrical event of Harold Pinter's superb screen distillation of Proust's A la Recherche du Temps Perdu. Both began life at Lamda and wound up being performed in full fig at the National.

Mixed Up North is a bracing, combative and oddly joyous example of this sub-genre. Professionally produced now by Out of Joint, under the auspices of the National, and beautifully directed by Max Stafford-Clark, it's a verbatim piece by the best of verbatim authors, Robin Soans. It tackles the intractable difficulties experienced by the Lancashire town of Burnley in the wake of the 2001 race riots and it approaches the subject through the story of a youth group who are about to dress-rehearse a show about mixed relationships. But the temperamental male star walks out and instead the group put on a Q and A session that turns into a compelling, almost Ibsenite, debate.

A council officer initiates a wrangle with the youth group, claiming to want to play down the town's racial and other difficulties so as to attract commercial enterprise to the place. Members of the group suspect this is a form of censorship masquerading as free-market enlightenment. There's something horribly unresolvable about the spat and this reminded me a little of the analogous situation where ruling regimes have a vested interest in saying that to stop fighting a war would be a betrayal of the combatants who have already laid down their lives for it.

Elsewhere, we hear of the difficulties of inter-racial marriage (and of the success stories in that area). We learn of the exploitation of underage white girls by Asian men who hook them on to addictive substances like heroin and enslave them to their whims. One Asian youth valuably attacks the liberal piety that arranged marriages are axiomatically less likely to succeed than those based on the Western notion of mutual selection through (often short-lasting) romantic love.

The acting is vivid and sharply etched across the board. At first, a play in which former acting students impersonate their beleaguered real-life counterparts might feel a bit like watching medical students perform an end-of-term revue about aspiring dentists. But then one recalls that Lamda's students come from a wide range of social backgrounds. Highly recommended.

To 5 December (020-7452 3000)