La Calisto, Royal Opera House, London

Flights of fancy on a Roman theme

When David Freeman electrified the British opera scene with his production of La Calisto nearly 30 years ago, Francesco Cavalli's 1651 sex-romp was put firmly on the map as a camp challenge. Freeman's singers did it on roller skates, and the image of the youthful Bonaventura Bottone whizzing seductively around lodged in the memory. The challenge has now been picked up by director David Alden and conductor Ivor Bolton, with a show that was such a hit in Munich, it's coming to Covent Garden.

Paul Steinberg's sets and Buki Schiff's costumes are wonderfully over-the-top. Jove decrees that the beautiful Calisto should join the immortals as a star, but she is bent on a life of chaste devotion to Diana. Frustrated, he assumes Diana's shape and tries to seduce her; the ensuing shenanigans end with her being enshrined as the bear-constellation Ursa Minor.

And who better to play Calisto than that sparkling soprano-comedienne Sally Matthews? "I'm in a leopard-skin swimsuit for the first half," she says. "In the second I add a caged outfit, which comes off for three minutes leaving me in my swimsuit, gloves and boots, plus my bow and arrow. At that point I'm supposed to be pregnant, which is David Alden's take on the story. And since I actually am five months towards having my second child, that's quite plausible." On the other hand, her swelling figure is less plausible in the first act, where she protests her undying chastity.

Vocally, she says, the production will break new ground. Since Baroque ornamentation was not written down, performers are free to choose their own, and Bolton's is unorthodox. The trills, says Matthews, are replaced by short staccato breaths. "We're also using 'white' tone, which sets off the sound of the orchestra, and heightens the colour of the harmonies. And in the first half I'm both dancing and singing, which normally don't go easily together. Basically, it's a very funny production – David Alden's imagination is as wayward as a child's."

In rep 23 September to 10 October (020-7304 4000)