Billy Budd, Barbican, London

It is a measure of Britten's innate theatricality that we might have been in an opera house and not Barbican Hall watching a motley crew of men standing to attention behind a row of music stands. The officers, it soon dawned, were in white tie and tails, the lower-ranked seamen were more casual.

The voice of Ian Bostridge was heard first over hazy strings oscillating between B-flat major and B minor. That harmonic ambiguity goes to the heart of the Prologue to Billy Budd, where Captain Vere looks back to the events of 1797 when he commanded HMS Indomitable. The vocal line is suffused with deep, abiding regret and immediately we are gripped by the elusiveness of his words. We want to know why. We want to go back in time. And we do.

Britten had the sea licked. He lived in close proximity to it; he heard its music. If you closed your eyes in this concert performance you were not on solid ground. Daniel Harding kept the internal rhythms astonishingly vital, while the orchestra scorned any difficulties, with trumpet playing, in particular, of dizzying brilliance. Most of all, it was Britten's nose for atmosphere that came through so grippingly. Is there a more thrilling moment in 20th-century opera than the crescendo of sailors' voices in the shanty "Blow her to Hilo"?

The good news is that EMI/Virgin were recording the performance. Good news, certainly, for Nathan Gunn, who looked the part as Billy but whose small voice somewhat compromised his physical charisma. Otherwise, Britten's ensemble of male voices made its mark. Neal Davies was an outstanding Mr Redburn; Andrew Kennedy's plangent tenor certainly made a fist of the Novice.

As Claggart, Gidon Saks deployed the curling lips, flared nostrils and fathomless bottom notes, chillingly turning his great "beauty" solo from aria to psychopathic rant in the blink of an eye. When Bostridge's Vere describes him as having "a hundred eyes" he does so with the audible revulsion of one who knows a monster when he sees one.

Bostridge's quality all derives from his immersion in the text. No one has made it clearer that Vere's salvation could only be achieved through Billy's death, that his failure to speak out on Billy's behalf betrayed a much deeper fear that admiration and love can prove too close for comfort when the love dare not speak its name. A masterpiece.