Four people bid each other a gentle goodnight: a short monotone from the chorus, two rising notes sung against a simple descending orchestral figure. What could be more peaceful and calming?

But no. This is the end of Act I of Britten’s The Rape of Lucretia, and the night is laden with threat: we know from the title what the night will bring. The voices of Christine Rice, Catherine Wyn-Rogers, Louise Alder and Duncan Rock are hauntingly beautiful, Leo Hussain and a dozen musicians from the London Philharmonic provide exquisite accompaniment, and the two person Greek Chorus of Allan Clayton and Kate Royal give an immaculately weighted intervention. And it is Britten’s unique genius to weave these different strands, each simple in itself, into a tapestry of tension.

Britten’s magic aside, much of the credit goes to Fiona Shaw’s direction of the acting. This Glyndebourne production of Act I of Lucretia puts each of its characters under the microscope and explores every nuance of their personalities, from the loutish Tarquinius – Duncan Rock, imposing both physically and vocally – to the power-hungry schemer Junius  – Michael Sumuel, dripping with venom – to the stoic Collatinus – Matthew Rose in reliably smooth voice – to Lucretia herself, played with dignity and passion (extraordinary that these two things can be reconciled) by Christine Rice and sung in a delightfully dark mezzo. But the individual vocal performances aren’t really the point here: it’s the ensemble acting and the steady winding up of tension that impresses.

The handling of the two person chorus is interesting: in early productions of the opera, they very much stand apart from the action, but Shaw has them more directly involved, weaving in and out of the action. The Male Chorus, Allan Clayton, is at the heart of some big coups de théâtre, one when he literally carries Tarquinius on his back, one when he excavates a sleeping Lucretia out of the earth.

Shaw and set designer Michael Levine start with an interesting concept: the whole thing is an archaeological dig in which the outlines of an ancient city (presumably Rome) become gradually more visible, a single floodlight perhaps standing in for our focus. Visually, it’s dingy: this is one of those productions where everything is dull browns and greys, and there is so little of Paul Anderson’s lighting that we don’t see a great deal more than the faces of the principals, and often, I couldn’t even make out the features on these.

While the overall concept convinces, Shaw grafts many individual ideas into the action. Without boring you with the details: some worked for me, others left me confused, others irritated. But regardless of what I may have thought of the concepts, I have rarely seen an opera with such consistently high quality of acting and in which the singers were so successful in bringing individual phrases to life. “The wound in my heart, Collatinus” filled us with worry, “But Lucretia’s virtuous” dripped with threat, Lucretia’s complaint of “How cruel men are to teach us to love” set up a magnificent trio. When Catherine Wyn-Rogers' ageing nurse Bianca implores Lucia to halt the messenger who will bring Lucretia's husband Collatinus home, because Lucretia needs time rather than words, we are heartbroken (Wyn-Rogers was the pick of the singers in pure beauty of timbre). And throughout, the small orchestra kept perfect balance, illustrating that every opera that Britten wrote contains music of an infinite variety of textures, each different from the others, always achingly haunting.

I find it hard to accept the ending. There are two premises: one, that Lucretia feels so sullied by the rape that in spite of the total support of Collatinus, she immediately follows the tender duet of the couple singing of how they are two halves of the same whole by stabbing herself to death. The second is that none of this matters since we now have Jesus Christ, which resolves everything. Now I’m not Christian and generally have difficulty with this kind of message, but in this case, I’m not even sure it’s good theology: Christian attitudes over the years to “virtuous pagans” have been decidedly short of unambiguously supportive.

All of which makes The Rape of Lucretia something of a problem piece. But setting this aside, this production is an excellent piece of ensemble theatre set around some very fine performances of music of rare beauty. Well worth the trip down to the leafy Sussex countryside.