The Comedy of Errors, Open Air Theatre, Regent's Park, London

"Ephesus welcomes you" blares the huge poster on the stage in Regent's Park, suggesting we are tourists on a summer outing, not a bad way of defining the merry mayhem in Shakespeare's farcical comedy of mistaken identity in a town full of cozenage and odd behaviour.

It's also one of endless coming and going, as in the Roman comedy of Plautus where Shakespeare found his mechanical plot. The Regent's Park revival by Philip Franks, colourful and zesty in the designs of Gideon Davey, keeps those doors flapping like windows on an Advent calendar.

Every time one door closes, another one opens, and the wrong person always comes through. But there's also a simmering international dispute: Ephesus and Syracuse are at odds, if not exactly war, and any Syracusan found in the town will not be as welcome as the rest of us.

Thus the old Syracusan merchant Egeon has been arrested and arraigned by a tall, white-suited Duke in a gendarme's hat that makes him look like General de Gaulle. Ragged and manacled, Christopher Ravenscroft makes Egeon's long, usually boring speech of explanation, one of riveting interest.

He's searching for his wife, Emilia, and their twin sons, and the sons' twin slaves. All of them are looking for each other, too, the sons both named Antipholus (because one of them was presumed lost in a shipwreck), the slaves both named Dromio (because, ditto).

Ephesus seems to have mutated into Casablanca in the 1940s, with Quinny Sacks's witty choreography presenting the complete cast of characters in a mood-setting dance sequence. This play is always veering towards music, and not just because Rodgers and Hart used it as a basis for The Boys from Syracuse; Trevor Nunn started his musical theatre career with a fizzing song-and-dance version at the RSC. So, the Porpentine brothel is turned into a cabaret café where Anna-Jane Casey's ripe courtesan steps out of her gorilla outfit in some rather complicated black lingerie. And the scheming sisters, Adriana (a sumptuously sarcastic Jo Herbert) and Luciana (pert and cheeky Sophie Roberts), exchange gossip on the nearby beach.

In a play all about displacement and transformation, the courtesan and her clientele – one of whom is thought to be the local but "errant" Antipholus of Ephesus (Daniel Llewelyn-Williams), married to Adriana – find further succour in a great Cole Porter song about deceptive appearances: "Is it an earthquake or simply a shock; is it that good turtle soup or merely the mock?" The pattern of sibling coupling will reassert itself when the literally errant Antipholus of Syracuse ("another Daniel", Daniel Weyman) meets Luciana...

Going round the corner and then finding yourself locked out of your own house is just one of the unsettling experiences they all undergo. No one's immune – there's something in the air – not even Richard Warrick's fussing little goldsmith. It's a carefully wrought and well-controlled production, dancing just this side of delirium, but just the job if the weather stays fine.

To 31 July (0844 826 4242)