Noises Off, Theatre by the Lake, Keswick

It is perfectly conceivable that you could sit through three acts of Michael Frayn's homage to the Great British farce and emerge thinking: "Thank God they don't make them like that any more". For anyone who grew up with the politically correct mores of the 1980s alternative-comedy scene, the idea of a theatre audience willingly subjecting themselves to an evening of unvarnished sexist stereotypes, double entendres, relentless running gags and, of course, those dropping trousers seems unimaginably alien.

So why then is Noises Off so fantastically, laugh-out-loud-couldn't-give-a-monkeys enjoyable?

One reason is that this production, at what must be the most beautifully located and friendly theatre in Britain, is performed with unadulterated brilliance by the cast. Ben Ingles is acrobatic with no apparent thought for his own safety as the play's increasingly demented leading man Garry Lejeune. So too Heather Saunders in fetching leopardskin underwear as the brain-dead but busty Brooke, while the rest deliver their roles with equal aplomb.

Another is that the play's conceit is brilliantly clever. A team of struggling actors take their under-rehearsed farce Nothing On through a grim odyssey of Britain's provincial theatres, culminating in an unhinged climax (fnarr fnarr) at Stockton-on-Tees. Prior to this we see the play from two other perspectives. First at dress rehearsal under the cruel gaze of its libidinous and deluded director, and then in a negative exposure – backstage, where the sad passions of theatre life on the road spill over in brilliant slapstick.

Frayn has admitted that writing this intricately plotted play was among the hardest things he ever did and fully expected it never to be performed. First staged in 1982, at the height of the alternative revolution when pants-down humour was on its last legs, it has continued to delight audiences and critics alike in repeated revivals not just in Britain but across the world.

There are obviously profound things going on this romp, although Frayn was forced into a rewrite when he tried to use the tawdry misadventures of our low-rent thespians to hold up a mirror to the human condition. They are still there but you're too busy enjoying yourself to bother looking for them.

In rep until 9 November (017687 74411)