At Opera North his work always struck me as patchily brilliant: capable of catching the nerve of a piece at one moment and losing it the next. There was a charming, chocolate-box Il Re Pastore. A Hamlet that was perverse, but no more than the piece deserved. A well-reviewed though, I thought, conventional Sweeney Todd. And a Don Giovanni whose striking, stripped- bare chic was, on reflection, the best of the three shows Opera North brought down to Sadler's Wells a month or so ago.
But in Alcina he emerges as a star. It's an exotic show, bathed in a golden radiance that not only looks amazing but finds exactly the right tone of voice to tell the story. Tone is the elusive quality in Handel opera, and it isn't easy to determine except by adjusting the relative input of baroque ingredients: whimsy, pathos, tragedy and heroism. For me, Nicholas Hytner's ENO Xerxes was a model of how it's done. And it seems to have been a model for McVicar, who borrows some of Hytner's knowing, glossily tight-lipped postmodern gestures in his handling of the chorus. As usual in Handel operas, they don't have much to sing. But undeterred, McVicar finds them work to do - dragooned into an onstage audience, a guard of honour for a bust of Handel (very Hytner that), and otherwise functioning as a collective 18th-century "presence", full of curiosity and reverent decorum.
Compared to Hytner, though, McVicar is more decorative, more gilded, and more wildly fantasist in his idea of the baroque. Alcina is a magic opera about a sorceress who ensnares potential lovers and turns them into wild beasts when the relationship goes wrong. A clear case of emotional insecurity. There's also a degree of gender insecurity as one of the main characters - a woman dressed for reasons of the story as a man - becomes the object of affection of another woman. McVicar plays with that idea, cross-dressing characters at will and casting a mezzo-in-trousers as the castrato hero when most directors these days would prefer a countertenor. Most conductors too.
It all becomes a fabulous, masque-like contrivance of the sort you would find in a Peter Greenaway film, busy with playful grotesques in punkish costumes, cutely sexy choreography, and a pervading sense of Alcina's magic island as a place of glamorous but dangerous dissolution.
Michael Vale's set - an architectural module after Palladio - is ravishingly beautiful. There's an extraordinary scenic trick to change the season and induce a sudden snowfall as Alcina sings her heart-stopping lament. And the unlikely thing is that, against all these diversions, the characters still register. With touching depth. Joan Rodgers makes a tender, vulnerable as well as terrifying sorceress. Sarah Connolly is robustly masculine in the trouser-role, Ruggiero. And the vocal star of the evening is Lisa Milne, who sings Morgana - the sexually confused sister of the sorceress - with captivating brilliance and vitality.
I was not so captivated by Sir Charles Mackerras's conducting, which is period-informed but of the older school. It could be crisper, sharper. But you'd travel far to find someone more solidly steeped in the idiom of Handel, and I'm not complaining. Shows of this quality don't come often enough to deserve anything but gratitude.
'Alcina': Coliseum, WC2 (0171 632 8300) Mon, Thurs & Sat and in rep to 27 Jan