George Benjamin took his first, much anticipated steps towards music theatre six years ago with Into the Little Hill, a contemporary retelling of the story of the Pied Piper to a text by dramatist Martin Crimp. That magical 40-minute piece, with two singers, a chamber-scale ensemble and minimal dramatic trappings, seemed wary of committing fully to such a treacherous, extravagant medium as opera. But working again with Crimp, Benjamin has now thrown that caution to the wind. Commissioned by the Aix-en-Provence festival, along with four other European opera houses including Covent Garden, Written on Skin is a fully fledged stage work. It may have only five singing roles but it belongs, unmistakably, in an opera house, unlocking so much more of the dramatic potential of Benjamin's music, which was kept on such a short rein in the earlier theatre piece.
Appropriately enough for a work introduced in Provence, the bleak, unforgiving scenario of Written on Skin comes from a 13th-century razo, the explanatory story behind a troubadour's song. A rich, powerful land owner, called the Protector in Crimp's libretto, commissions an artist, the Boy, to celebrate his life and the achievements of his family in an extravagant illuminated book. As the Boy painstakingly creates his manuscript, he attracts the attentions of the Protector's much younger wife, Agnès. His imagery empowers her, and she begins to assert her independence as a woman, rejecting her role as the childish property of her husband, to the Protector's angry dismay. So, he brutally kills the Boy, and forces Agnès to eat the heart; she then jumps to her death from a balcony before he can kill her, too.
Crimp's finely chiselled text gives the story a contemporary perspective by having three characters he calls Angels bring the medieval figures back to life and reflect on what happens, and by having the protagonists, especially the Boy, sing about themselves and their actions in the third person. That shuttling across eight centuries is taken farther in Katie Mitchell's staging, which seems to depict the angels and four other extras as present-day archaeologists re-enacting the events described in the manuscript they are restoring; Vicki Mortimer's set is divided between past and present, too: the archaeologists and their work to the left; the medieval tragedy unfolded to the right.
Some of those directorial glosses seem fussy and distracting, as if Mitchell were determined to leave her own mark on a work that seems perfectly self-contained dramatically anyway; they clarify nothing at all. What drives the opera's three parts (with the briefest of pauses between them) far more effectively, however, is Benjamin's score, which is more impassioned, more sensuously beautiful and, at times, more fiercely dramatic than anything he has written before. The intertwining of the voices of Agnès and the Boy, soprano and counter tenor, often with just the sparest accompaniment, is spell-binding; the ability to crystallise a whole mood in a single mysterious orchestral chord or a bare, ticking percussion clockwork is magical. The large orchestra is used with maximum restraint, given its head only in the interludes that separate some of the scenes; Benjamin himself conducts and the Mahler Chamber Orchestra play wonderfully for him.
The cast is remarkable, too. Barbara Hannigan compellingly charts Agnès's growing self-awareness, and wraps her voice ravishingly around Benjamin's high-lying vocal lines; Christopher Purves manages to give a human dimension to the Protector's cruelty. Bejun Mehta is the honey-toned Boy, the unwitting catalyst for all that happens; Rebecca Jo Loeb (a late replacement) and Allan Clayton are the other Angels. What Benjamin and Crimp have done is remarkable, whatever the shortcomings of the staging.
• Until 14 July. Box office: + 33(0)4 34 08 02 17. At Royal Opera House, London WC2 (020-7304 4000), 8 to 22 March.
