A Funny Thing Happened on the Way to the Forum, Olivier, NT, London

The rousing opening number is a brazen sales pitch - "Something that's gaudy,/ Something that's bawdy/ Something for everybawdy/ Comedy tonight!" - but the knowing cheek of it is irresistible.

The rousing opening number is a brazen sales pitch - "Something that's gaudy,/ Something that's bawdy/ Something for everybawdy/ Comedy tonight!" - but the knowing cheek of it is irresistible. Besides which, as Edward Hall's blissfully hilarious revival now demonstrates, A Funny Thing Happened on the Way to the Forum succeeds in living up to this hectic hype. With an entire chorus emerging from a theatrical wardrobe basket and a climactic high-kicking line-up five minutes in, the prelude here seems to head straight into a rip-roaring finale.

And that piece of self-mocking gamesmanship is just right, because this 1962 Broadway musical - boasting a glorious gag-fest of a book by Burt Shevelove and Larry Gelbart and the first score for which Stephen Sondheim wrote the tunes as well as the lyrics - gives a spoofing American vaudeville spin to the Roman farce conventions of the dramatist, Plautus, a third century BC guy who had earlier helped Shakespeare with the plot of The Comedy of Errors.

A delirium of good, clean, filthy fun, the plot is officiated over by the wily, manipulative slave Pseudolus who has to struggle with the escalating complications that ensue when he attempts to gain his freedom by securing a match between his master's blonde, dim-witted, virginal son Hero (Vince Leigh) and the even blonder and dimmer courtesan, Philia (Caroline Sheen). The course of true chicanery never did run smooth, and the premature return of his master, who has already bought but not collected Philia, send the collective blood pressure on stage soaring.

The delicious thing here is that, at the centre of this cartoon heterosexual frenzy, we have, playing Pseudolus, the splendid figure of Desmond Barrit, who is all the more hysterical for being fundamentally unfussed, constantly tipping the audience the wink that we're watching a piece of theatre, and as incongruously camp as row of Welsh wigwams. When the courtesans (Vibrata, Gymasia, Panacea et al) perform a gynaecological version of the splits for potential clients, his lower lip quivers. Around him, pandemonium reigns - and this is wittily embellished in Hall's production.

While never propelling the proceedings, Sondheim's songs offer well-placed commentaries. The stand-out number is the libidinous "Everybody Ought to Have A Maid", which builds, applause from duet to trio to quartet, and features Sam Kelly, sublime as Hero's grimacing, randy father. It's an object of such devotion that he chucks it into the stalls the moment he gets wind of a better offer. It adds to the gaiety to think that quite a few these jokes must have been ancient when Plautus was a lad. He'd have a ball at this cornucopia of delights

In rep till 2 November 2004, (020-7452 3000)