Theatre: Carry on cowboy

"WARNING: This show contains material that might cause offense." Thus spake the unusually winning press release for Yee-Haw!!, the self- styled "crazy, camp, cross-dressing cowboy" musical (right). Affixed beneath this fearfully stern warning was a shocking example of this downright degrading material: a piece of purple gingham.

Well, darn it, I was off down that there theater swifter than a sharp- eyed shoot-up at a hoedown. Yup, this pistol-packin' show's got everything: stampedin' buffalo, thigh-slappin' cowboys, and painted cacti. Heck, the audience even enter through a pair of swinging saloon doors. Fine-talkin', fresh-faced Luke Calhoun (whose mother taught him decency, truth and righteousness) heads off to Red Rock in search of his father's gold, which just happens to be buried in the basement of his new landlord, local sheriff Wilt P Haversack, who lives there with his sharp-shootin' Sapphic daughter, Cindy-May.

However, our hapless, hopeful hero hasn't reckoned on the wiles of wicked JF and his Red Indian sidekick Hank, who will stop at nothing to find the loot. They even cut local whore Lulabelle into the deal, who tries to persuade Luke to "ride shotgun on the Bed-wood stage..." (This show has less political correctness than the AGM of the Ku Klux Klan.) Luke is taken with Red Rock's quaint main drag, but JF heads him off at the pass. "I've got four words to say to you," he growls, threateningly, "Out- of-town shopping..."

Anyone expecting an operatic treatment of Dances with Wolves or High Noon with high notes should saddle their horse and gallop off in the opposite direction. The budget for Gregg Harris's perky, shoestring production (splendid painted sets by Jan Rosser) wouldn't even buy a bootlace tie for the National's upcoming Oklahoma!, yet the alacrity with which the audience supplied the odd special effect is testament to the fun we were all having.

In the cold light of day, it must be admitted that Peter Shrubshall and Richard Free's music and lyrics may not cause Stephen Sondheim to consider a career change. But hang on there. Like most of the score, the duet "Just a Matter of Time" is generic Country-'n'-Western-meets-showtune spoof, but despite spending most of it switching (hilariously bad) costumes, boisterous boy-hating Cindy-May and newly-liberated Luke manage to make it genuinely touching. The whole cast deliver the numbers with an insane and insanely funny enthusiasm, particularly "Rip-Snortin' Woman". Best of all is the lunatic Act Two opener in which the six-strong energetic cast leap into the captivatingly daft "Sing and dance/For no particular reason". Clint Eastwood gave us Unforgiven. What these varmints have cooked up is Unforgiveable but a heck of a lot funnier. Mind you, what can you expect from a director who lists previous career highs as Ibsen in IKEA "which caught the pine essence and functional morality of the piece" (Furniture Monthly).

Yes, the choreography is a little cramped. Yes, a little cutting wouldn't go amiss, but the sense of fun is completely infectious thanks to the cast. As naive Luke, Nick Atkinson is superb. He gives the whole kit'n'kaboodle a bizarrely truthful centre. He has split-second timing, but instead of using it for cheap laughs, he builds his hilarious double-take bafflement and innocence into his character. Danny Charles is also memorably daffy, doubling as Hank and dangerously high-pitched Black Jack Jackson. The whole shebang makes Blazing Saddles look like Gibbon's Decline and Fall. This supremely silly show is destined to become a cult. It deserves to run and run.

The Rosemary Branch, Shepperton Road, N1 (0171-704 6665) Tue-Sat 8pm, Sun 4pm to 22 Mar