When the curtain calls are taken, it is, to say the least, unusual, for a principal to mouth "Sorry!" to the audience – who only clap their approval even harder. For Christopher Purves had nothing to apologise for: he had succumbed, as we all do, to a throat infection, and had to lip-synch his role as Protector in George Benjamin's Written on Skin on the second night of its short run at the Royal Opera House. His fellow baritone James Cleverton nobly sang the role from the score, at the side of the stage.

That Cleverton could not simply chuck on a smock and step through the role himself, which would have happened in some repertoire operas, illustrates the precision of the physical drama in this arresting modern opera. Indeed, the role was created by Benjamin with Purves in mind, as the singer explained in his interview with Culture Whisper. As the controlling husband of Agnes – "her body is my property" – he is slow to believe, then murderous, when he discovers that she has slept with a young man he has employed.

This character, known simply as the Boy, is a scribe and illustrator commissioned to write a lavish and impressive account of the vain Protector's family line and lands. While on the one hand thinking nothing of burning villages that do not fit his plan, on the other he is a frank admirer of the Boy's beautiful craft. There is no shortage in history of tyrants with a soft spot for beauty.

The apparently simple and familiar tale of a loveless marriage, an affair, its bloody end, is told by Benjamin's luminous music and Martin Crimp's crystalline libretto with such painterly and poetic skills that the opera completely mirrors the book from which the events spring – something of silky wonder spun from old threads.

Packed with references to art, literature and music, Written on Skin wears its rich artistic heritage lightly, and it is for the audience to find and to savour its lineage, from the solemn interiors of Vilhelm Hammershøi and the Dutch masters to the operatic fates of Tosca and Senta. Benjamin's thistledown music tumbles through the air as if supported by the three Angels who look down on this long-past tragedy from the steely modern world, support its telling with sacramental care, and also step into the action, as the Boy, and as Agnès's sister Marie and her husband (Mark Padmore in this luxury casting).

This first Covent Garden revival since its UK premier in 2013 of Written on Skin is again directed by Katie Mitchell, who tailors the drama as fluently as the Boy writes, forensic observation giving way to suggestive eroticism to cruelty, and finally, to release. Vicki Mortimer's gradually evolving design, the balance between modern and ancient worlds shifting in each of three parts, and Jon Clark's lighting palette favour the monochrome: all the colours, "azzurite and gold", are in the Boy's illuminated book.

Georgia Jarman sings two of the five performances, Barbara Hannigan, who created the role of Agnès, the other three. Jarman's unfettered, highflying soprano is as translucent as Benjamin's gossamer-light orchestration. Even voiceless, Purves is powerful and menacing.

As for Davies – well, here's the biggest riddle in music today: can this already outstanding voice keep on and on getting better and better, when it always seems to be beyond compare? Make no mistake, this is a voice to hear at every opportunity; we may wait a generation or longer for its equal. Catch him again in Covent Garden's The Exterminating Angel soon, or at the Aldeburgh Festival, or in Bach's St Matthew Passion, or at St John's Smith Square's Holy Week Festival, but don't miss him. And don't miss this.