Iphigenie En Tauride, Royal Opera House, London

A woman in black emerges and makes her way slowly downstage. This is Iphigenie; her name is chalked up on the back wall by a shadowy group of other women. All hell then breaks loose. A terrible storm shakes the orchestra, orange light floods the stage, and a recurrent nightmare replays in Iphigenie's imagination: the murder of her father, Agamemnon, by her mother, Clytemnestre, in turn despatched by her brother Orestes. And because blood is thicker than water, Robert Carsen, the director, splashes bucketfuls of the latter all over the stage as if to remind us that it might be possible to wake from this bloodbath.

Only minutes into Gluck's Iphigenie en Tauride and already you are thinking: "Follow that." Carsen does, but – and it is a big "but" – he essentially takes the Greek chorus out of the Greek tragedy, and casts it into a parallel underworld offstage, where it can only be heard. How diminished its impact is as a result is the big issue here.

From a musical standpoint, the force and immediacy of Gluck's choral writing is compromised by its remoteness. In the lachrymose finale of act two, where Iphigenie, convinced that her entire family is now dead, proclaims "Let us now mingle our mournful cries" and Gluck responds with a great ensemble pierced by the pain of a single oboe, collective power is everything.

Instead, Carsen pulls visual focus on his dancers. They are the physical embodiment of his chorus, a shoal of writhing, seething, bodies whom choreographer Philippe Giraudeau treats as an expressive underpinning of the sung text. One could argue that this is an opera about isolation, and the extra physical dimension is too much of a distraction. I didn't. I thought it lent the staging an impulsive energy.

Simon Keenlyside is Orestes, full on as ever, though he should beware that body language does not dictate feeling and thought, but rather the other way around. Paul Groves was immensely truthful as Orestes' friend Pylade, his singing resolute and direct.

Gluck's score – realised with such immediacy by Ivor Bolton and the Orchestra of the Age of Enlightenment – bristles. Gluck's nose for atmosphere and dramatic timing is everywhere. And Susan Graham's superb Iphigenie played the moment to perfection. She didn't wear her grief and anger in this performance, she carried it within herself.

Until 29 September (www.royalopera.org; 020-7304 2000)