ALMEIDA OPERA / The raw food of life: Robert Maycock on the Barker / Osborne collaboration, Terrible Mouth

The massive tilted stage thrusts out towards the audience, and bisects the Almeida Ensemble: a group of players tucked to one side, a row of cellists high up at the back. Even before Terrible Mouth has begun, Nigel Lowery's designs tell you plenty about the intimate relations of acting and music. The first sounds emerge on the fringes of speech and song, a macabre birth ritual over a quiet timeless drone. Gagging noises evolve towards the elements of human utterance and the first hints of melody, as the Chorus of the Maimed spews out of the darkness. It is as clear a declaration of aims as the Almeida Opera Festival could have come up with.

Howard Barker's collaboration with Nigel Osborne, commissioned by BBC Radio 3 and premiered on Friday, takes the work of Goya, amid the carnage in Europe after 1789, as an entry-point to the messy confusion of art's dependence on reality, and the moral chaos in which artists feed off the life around them. It is not a slice of biography: the Goya figure, doubly cast as an actor and a singer, entangles himself with a symbolic, military Man Without a Conscience and with an all-flesh- and-blood Duchess of Alba, but he is there to resolve his dilemmas. He realises he can accept the unacceptable as the raw material of creation, at a cost that is total. Love turns to hate, the unforgiving eye turns the human being into an object, and the painter deliberately shuts out his own light.

If this is firstly a play of ideas, the thought springs from and dwells on extremes of emotion, and the need for music is inbuilt. Barker meant Terrible Mouth to be an opera text from the start. It reaches heights of pithy, sometimes violent eloquence, and Osborne's score supports rather than dominates it. Mostly slow- moving, the music paces it over a single act of around an hour and a quarter, with speech rhythms taking the lead over free melodic expression and subdued instrumental support which springs into passing beauties of detail. Its most distinctive feature is the choral writing, for a mixed group of singers and actors, and continuing as it began with a language that grows from instinctive, animal sounds.

The impact is disturbing, not conventionally 'musical', and the whole piece is strong meat in several ways: severed limbs and corpses are flung around, the text does not flinch from coarseness, Goya's final speech overflows with disgust for womanhood. But, despite the intensity of the events, there is little over-riding sense of dramatic development and change, except in the words. Goya tells us what is happening to him, and the staging shows us. We are shocked, but not caught up in it. Maybe the problem was bound to emerge with a first libretto which was written without any composer in mind: Osborne only came in afterwards, and the musical dimension feels restricted. The opera certainly explores, but it does not fully emerge, and the aims feel tantalisingly just out of reach.

At least it was able to evolve on stage. Much of David Pountney's powerful production goes well beyond what the printed libretto asks for, entirely to the benefit of the work, and David Parry conducts some galvanising individual performances. Omar Ebrahim sings a fluent and scathing Goya, Ian McDiarmid speaks an alarmingly explosive one. Elizabeth Laurence, Tinuke Olafimihan and Richard Van Allan meet him - or is it them? - with particular forcefulness.

Supported by the European Arts Festival, the John S Cohen Foundation and the David Cohen Family Charitable Trust.

Further performances 15, 16, 18 July, Almeida Theatre (071-359 4404)

(Photograph omitted)