Hercules, Barbican, London <!-- none onestar twostar threestar fourstar fivestar -->

We think we know Handel these days, but he's still full of surprises: the rarely performed Hercules sheds unexpected light on his mercurial genius. This "musical drama" didn't get much of an audience when it was premiered in 1744, but the cognoscenti recognised its quality: it offered a startling new take on the death of a legendary hero, and it reflected morbid psychology through music in a way far ahead of its time.

For the director Luc Bondy, it tells of a man who massacres a city for a girl: not such an outlandish idea, given that Napoleon did the same, but fertile in its extremity, as is Bondy's conviction that the crazed jealousy of Hercules's wife Dejanira is the motor for the plot. The macho conqueror comes home from war with a captive princess in tow and scarcely a glance at his wife: to re-arouse his desire for her, she takes the envenomed shirt of one of his slain enemies and puts it on him, in the belief that it will act as an aphrodisiac, but it kills him instead.

For William Christie, the conductor, this opera offers a kaleidoscope of voices against a sumptuous choral backdrop over ingeniously deployed strings. His company, Les Arts Florissants, rise superbly to the challenge. It was bad luck that a throat infection silenced Ingela Bohlin as Iole the captive princess, but with her stand-in Hannah Bayodi singing lustrously from the pit, the pathos of Iole's predicament was oddly enhanced.

The production got off to a poor start for two reasons: mezzo Katija Dragojevic has a lovely voice, but not a word of her scene-setting recitative was comprehensible, and the stage business she was asked to perform with a pomegranate and the curtain was similarly opaque. But once in full swing, Bondy's production works wonderfully. He's taken imaginative liberties, which the floridly declamatory text virtually invites, but his updated story totally convinces: Hercules's son Hyllus sets off to discover his father's fate with a road map plus rucksack-gifts from members of the chorus; Iole's lovely aria about her quest for love is turned into an attempted seduction scene in which Hercules showers her with gifts; Joyce DiDonato's Dejanira physically expresses her lustful scorn for her errant husband by ripping off first his medals then his clothes.

And what a performance DiDonato gives - colouring every phrase with exquisite musicality, pervading every scene with her sulphurous rage. And what marvellous foils she has in Ed Lyon as Hyllus and William Shimell as Hercules: Lyon's pure tenor shifts effortlessly into counter-tenor when the occasion demands, while Shimell's bass thunders majestically. Dominated by a dismembered giant statue, the staging is brilliantly effective in its evocation of a timeless Middle-Eastern world of blood, fire and vengeance.

Ends tonight (020-7638 8891; www.barbican.org.uk)