Cosi Fan Tutte, Glyndebourne, East Sussex <!-- none onestar twostar fourstar fivestar -->

A serious look at comic opera

The fleeting exchange of glances in the final seconds of Nicholas Hytner's new Glyndebourne production of Cosi fan tutte does more than suggest that new infatuations will not easily be shaken off: the pupils in Mozart's "School for Lovers" may have learnt the hardest lesson of all - that love is fragile, and you toy with it at your peril. It's one of many tiny details in Hytner's staging that make this the closest thing to a Method Cosi that I have ever seen in the theatre. It's soundly motivated, keenly observed and honest to a fault. So why isn't it enough?

The key may be in Hytner's earnestness. For the first half hour, right up to the point when Ferrando and Guglielmo return in disguise, this Cosi was so tasteful, so well behaved, that it almost died of good intentions. Looking pretty as a picture in Vicki Mortimer's curvaceous, marble-faced set, it had a squeaky-clean feel, and the pacing and mood were leisurely and genteel.

It's true that the complexion of Mozart's ravishing score is for the most part diaphanously feminine, and that was something that Hytner and his wonderfully sympathetic conductor, Ivan Fischer, together with the soft-grained colours of the Orchestra of the Age of Enlightenment, were keen to - and did - exploit. But I'm not sure you can play the recitatives with this kind of studied naturalism. It felt slow. It felt flat. And with Hytner also determined never to play for laughs that weren't earned (and if that's the case, how on earth do you get around the antics of Dorabella's maid, Despina?), it felt po-faced.

So many opportunities were missed with Don Alfonso, who in the nondescript figure of Nicolas Rivenq almost disappeared from the proceedings. He was neither a sinister presence nor the pace-making master of ceremonies that Mozart envisaged. He even sang raggedly.

But with the return of the boys convincingly disguised as the two musketeers - all flouncy clothes and louche manner - things began to look up. The casting was spot on, and, as you might expect from practitioners as perceptive as Hytner and Fischer, the musical line as well as the words dictated much of the humour and heartache and anger.

Miah Persson and Anke Vondung were beautifully matched as Fiordiligi and Dorabella. They played off each other like sisters, their kinship as marked as their individualities. Vondung was an unusually characterful, feisty Dorabella, and Persson a beautiful and touching Fiordiligi. Very much the big sister, she directs the second stanza of "Come scoglio" to Dorabella alone. That's a nice touch, which says, "I know you - but you must stiffen your resolve."

Later in the evening, of course, it is Fiordiligi who must wrestle with her conscience. "Per pieta", that most challenging of all arias, was not only a super piece of singing; it was a real emotional journey.

On the masculine side of the equation, Luca Pisaroni's Guglielmo played winningly, darkly, on the braggadocio, while the engaging Finnish tenor Topi Lehtipuu used the gentle flutter in his voice to caressing effect and displayed delicious cool when his sword got tangled in his cape as he launched into the single most romantic expression of his heart's desire, "Un'aura amorosa".

And Despina? Well, for all her charm, my feeling was that Ainhoa Garmendia was too young and unworldly, and that the role in fact demands a more experienced pair of hands to square up to Don Alfonso's wiliness and cynicism.

Musically, though, it was a strong evening, with Fischer and the OAE really underlining the conflicting masculine and feminine characteristics of the score. I'm still not sure why it didn't add up for me. Perhaps, for all the darkness at the heart of the piece, Hytner's staging simply took itself a little too seriously.

To 10 July (01273 813813)