This is a four-star-for-fun review, with slight style reservations. Straggly wigs, wilting hem-lines and a tactical misuse of the show’s biggest number – “Fascinatin’ Rhythm” – as an overture with dancers picking their way too gingerly down a scenic piano keyboard, are not good for the nerves.

But what a joyous, well-written show this is, not just for its music and lyrics by George and Ira Gershwin, collaborating for the first time on Broadway in 1924, but also for its book by Guy Bolton and Fred Thompson. They provide zany, surreal comedy and the best worst musical theatre gag I’ve heard in a long time: “The girl’s doing five years in Canto Canto; that’s Spanish for Sing Sing”. Okay, you have to be there, and perhaps you should be.

Fred Astaire and his sister Adele were the first stars. Their roles of Dick and Susie Trevor, siblings suddenly fallen on poverty row in Rhode Island, are charmingly taken by blond, high-cheek-boned Chris Ellis-Stanton and muscular, appealing Kate Nelson, who means business in every number.

The choreography by the brilliant Bill Deamer is unsurpassed in current London musicals, unless you want to stick around for Deamer’s work on The Boy Friend at this same address next month. The ticket price is worth it just for the bull-fight sequence which segues into a madcap rumba.

Ian Talbot’s production gains an irresistible momentum under the swaying trees and twinkling lights. Paul Farnsworth’s design is suggestive of camp cabaret nights in fringe venues, or a Sondheim evening in Chichester, a folly of a giant tilting piano (with a Manhattan skyline growing out of the interior), an over-scaled white cello covered in glitter and a drumkit-cum-stairway.

But it works really well. This is the definitive jazz age musical, wearing its social significance lightly, but wearing it anyway, along with the frantic fashions and arch wistfulness. Not only the title song, but delightful items like “Sweet and Low Down”, “So Am I”, and the surprise bonus of “Little Jazz Bird” (sung beautifully by Rachel Jerram with a sympathetic male chorus line) keep your ears pinned all night.

Paul Grunert scores a breakthrough success as the wise-cracking lawyer who initiates Susie’s get-out as a spurious Mexican heiress and ends up handcuffed to a lovesick dip-stick on his wedding night (“But my pink pyjamas are at the laundry!”).

The siblings sort out their romances after Susie’s soulmate, Jack Robinson (Norman Bowman), graduates from unlikely hobo to top-drawer, hotel-owning bozo, and society hostess Josephine Vanderwater (Hattie Ladbury, hilarious as a version of Fiona Shaw possessed by Bette Davis) oversees yet another high society social shindig. Basically, it’s party time in the park; if the weather’s clement, there’s no better place to be.

- Michael Coveney