And, of course, the virtue of a concert (or "semi-staged", as was the case here) performance is that, installed as we were on the main deck of the great ship Barbican, there is no cover for the sound. The "infinite sea" was out there, open before us.
And with conductor Richard Hickox going for optimum impact at all times - his seafaring zeal sometimes exceeding the boundaries of a viable voice- to-orchestra ratio - the visceral impact of the London Symphony Orchestra and Chorus was considerable.
The thrill of the shanty "Blow her to Hilo" gradually rising from below decks to an overwhelming crescendo, Britten's multi-layered voices breaking like cresting waves against the clean, bright sound of violins and high trumpets - as if to endorse Captain Vere's idealism. Or the call to arms in Act 2, "This is our moment", beating drums and hollering voices from all quarters, the English choral tradition cast to the last force-10 gale in the saltiest full-on singing this mass assemblage of men's voices could muster. And that's the other thing about this score: Britten finds many colours across the range of male voices. Many dark shades.
None darker, of course, than the craggy basso profundo in which the soul of the evil master at arms, Claggart, is entombed. John Tomlinson was all dungeon-black rhetoric and sinister insinuation, an incongruous charm inviting his "prey" to "come closer" into his confidence. The anger in his Iago-like credos was revealing. Billy was so plainly the object of his desire, the love that dare not speak its name, if only he could feel love, the everything he wanted to be but could not be. By contrast, Philip Langridge's Vere, was goodness personified, but it was a goodness smothered by an unshakeable sense of duty. Duty before humanity at the moment that really mattered, the moment at which he could have saved Billy's life. In just two words, "I cannot", Langridge - the most truthful of artists, one whose every thought process you can actually follow - conveyed a broken man.
Simon Keenlyside was a fresh and wonderfully physical Billy. His body- language contributed greatly to the vocal performance in an evening - despite the concert setting - full of physicality. Officers in evening dress, seamen in nautical civvies, busily came and went: even the podium guard-rail came to suggest the prow of the vessel. Individuals emerged from among the motley crew: Mark Padmore's Novice, Francis Egerton's Red Whiskers, Richard Coxon's Squeak, Clive Bayley's Dansker.
But Britten's great skill is in the ensemble. And the orchestra. It's true that nothing can prepare you for the infinite succession of triads that accompany Vere - "the messenger of death" - to the condemned Billy like so many questions and answers. And it's equally true that as Billy's body plunges from the yard-arm, one's heart will forever be in one's throat as the music spirals upwards, the last remnant of Billy's soul vanishing in a wisp of violin harmonics. That's genius.