Michael Billington: Michael Frayn, as we all know, is a hugely massive intellect and has written plays about nuclear physics and all sorts of things but Noises Off is a backstage farce really, and it's about it's about what happens when a farce goes wrong. And it just gets the audience in paroxysms of laughter; people claim to have seen people literally rolling in the aisles in this play with uncontrollable laughter. But like all Frayn's plays there's an idea behind it. And what he's saying is we try to impose order on life but chaos is always there underneath and is about to erupt. And what he shows, of course, is what happens when a farce, the most disciplined of forms, surrenders to chaos and disintegrates on stage...