Stir one part "My Fair Lady", one part "Mary Poppins" and season with a little "Pirates of Penzance" and you might just get Darling of the Day (at the Union Theatre until 20 April).
Opening on Broadway in 1968 just in time to coincide with the end of the British invasion and the dawning of the Age of Aquarius, it closed after 31 performances, a victim of that most crucial element in any success or failure - timing. But it's back and on the London stage for the first time and one can only wonder why it took so long.
After a 20-year Gaughinesque sojourn in Java, celebrated artist Priam Farll (James Dinsmore) returns to London dreading the prospect of resuming his life amongst the salons and galleries of the art world. When his valet, Henry Leek, dies suddenly, Farll seizes the opportunity to indulge in a little identity theft and becomes Leek, leaving his valet to be mourned by royalty and buried in Westminster Abbey. He also picks up Leek's appointment with merry widow Alice Challice (Katy Secombe), who has been corresponding with Leek with a view to marriage. To his surprise, Farll falls in love with Mrs Challice and her life amongst the salt of the earth Londoners, but when Farll fan and collector Lady Vale (Rebecca Caine) and unscrupulous dealer Clive Oxford (Michael Hobbs) uncover some new Farlls in a downmarket Putney framemakers, their corner in the market is threatened and a court case looms.
If that sounds rather serious, well, so do summaries of Gilbert and Sullivan's works, but, like any Savoy Opera, it's actually silly, clever and huge fun for everyone involved. Mr Dinsmore is charming as the Eliza Doolittle in reverse, and Ms Secombe channels Barbara Windsor's feisty vulnerability perfectly. There's plenty of decent tunes, a few barbs cast in the direction of commodity art and spectacularly energetic dancing in such a small space - and if it lacks a showstopper, there are no duds in the score.
Darling of the Day is not going to change the face of musical theatre, but it makes for a lovely evening full of warmth and wit, marking another success for the Union Theatre's policy of unearthing neglected musical gems. Long may it continue.