Mozart's final attempt at opera seria is fraught with difficulty. Written hurriedly and "on the move" from Vienna to Prague in the last weeks of his short life, the whole was never equal to the sum of its best parts. The great moments stir and exalt, but vast swathes of secco recitative need extremely careful, not to say urgent, attention. Not treading water, these recitatives are the very life-blood of the drama. And McVicar, to his credit, knows it. He and his conductor, Roland Boer, work hard on the tension and release inherent in them; the continuo of harpsichord (Boer himself) and cello (David Newby) does more than merely punctuate. And though word audibility is still an intermittent problem in this huge auditorium (it does lack immediacy for repertoire on this scale), the body language of a uniformly excellent cast invariably speaks where words may not.
McVicar and his designer, Yannis Thavoris, make much of the opera's magnificent austerity. The wilful mix of styles and cultures reflects the long history of autocratic rule and gives the drama a reach far beyond ancient Rome. Tito's personal bodyguards, for instance, display great facility in the ancient art of kendo. Visually, this is a seductive show. The stage pictures evolve through a series of curved, sliding screens - one adorned in exquisite detail from Japanese silk-embroidery; another of carved lattice-work, like that of a confessional. There is a wonderful sense of the conspiratorial; of desire breeding contempt around every blind corner. Paule Constable's crepuscular lighting heightens the intrigue with ominous shadows.
And what a cast. Even the younger lovers, Servilia (the radiant Sally Matthews) and Annio (Stephanie Marshall), shine in ways that keep the evening finely balanced. In the case of Sarah Connolly (Sesto) and Emma Bell (Vitellia), whose reckless desire is at the heart of the drama, we're talking international quality. Connolly would (and should) now grace any stage in the world. She sings nothing that you don't believe - not a false, disingenuous note anywhere. In her great act one aria with clarinet obbligato (Anthony Lamb), she stills the auditorium with the intensity of the words, "Look at me!" - because we know (and so does she) the consequences of that one look from Vitellia.
Bell's Vitellia is fabulously manipulative. Her scorn - and the fiery coloratura which underscores it - fills the house. Her top notes are not just thrilling in themselves - Vitellia's arrogance is directed through them. So that even as she finally resolves to do the right thing and confess her treachery to Tito, her self-righteousness is expressed in hands lifted triumphantly above her head.
That image magnificently complements the arrival of Tito for the last scene - Mozart's lofty processional as uplifting as anything he put on the page. In this notoriously tricky role, Paul Nilon achieves a high degree of believability and vocal accomplishment; brave, meaningful pyrotechnics in his difficult final aria underlining his unshakeable compassion. At the close, his clemency bestowed, he gathers up his lengthy golden train and seems to totter under its weight as if the burden of the compassionate ruler is just too great. It is. An exceptionally classy evening.
To 8 March (020-7632 8300)