A camped-up caper with a royal ruse

Simon Callow directs a rare staging of a witty masterpiece by a luminary of the belle époque

Chabrier knew everybody. He was painted by Manet, he collaborated with Verlaine, he drank with Duparc, Chausson and D'Indy. Several of his operas - Gwendoline, L'Étoile - still have a claim to fame.

Simon Callow is directing Chabrier's Le Roi Malgré Lui (The King in Spite of Himself), arguably his masterpiece, for Grange Park Opera. A comic spoof about a homesick, lovesick Frenchman who is elected King of Poland, its story is bizarre: disguised king joins plot to murder himself, plotters fall for the ruse, many red herrings ensue, etc.

Sounds like a send-up of A Masked Ball. Does it work? Wasfi Kani, the brains behind Grange Park's forays into French 19th-century opera (it recently staged Messager, and she has Reynaldo Hahn in her sights), reckons so. "Chabrier is a great, great composer," she says. "People know España - and that's about all. Actually, he's France's Puccini. Le Roi Malgré Lui is a glorious opera - easy on the ear, rousing, amusing, a great vehicle for Chabrier showing off in different styles (he adored Wagner and Berlioz). There aren't just one or two good tunes in it - you go from one fabulous number to another.

"As none of the Poles has seen the new king, Henri de Valois [Stephen Logues], he's able to infiltrate the plot in disguise, and even offers himself as the assassin. There's a further twist: he's had an affair, in Venice, with a masked lady, Alexina [Mary Plazas], one of the plotter's wives. As neither knows who the other is, the confusions multiply!

"There's a ballroom scene to die for, riddled with mazurkas and polonaises, in a chandeliered hall. And we're doing it - unusually for these days - in 'period' costume. Simon Callow, Renaissance man that he is, has got Ashley Martin-Davies to do the designs, and they look amazing. Kit Hesketh-Harvey has translated the songs - such as the king's 'Romance' and the 'Gypsy Song' - and Simon the spoken text, which he has camped up with racy jokes. Grange Park now has a huge new stage and pit, so we've got a large chorus and orchestra; you need that for Chabrier's lush orchestration. And there are four amazing dances, choreographed by Quinny Sacks."

Chabrier didn't have much luck in his day. After three performances in 1887, Paris's Opéra-Comique, with all his sets, burnt down. The King of Poland never made ripe middle age, either: he really was assassinated, in 1589, by a fanatical monk. Scope for another opera, perhaps?

Grange Park Opera Festival (including 'La Bohème' and 'Iolanthe') continues until 11 July. 'Le Roi Malgré Lui' starts on Saturday (020-7320 5408; www.grangeparkopera.co.uk)