Tristan und Isolde, Op&eacute;ra Bastille, Paris <br/> Maggini Quartet, Purcell Room, London

Big themes, big voices, enormous videos

First seen in Los Angeles in a series of concert performances, Peter Sellars, Bill Viola and Esa-Pekka Salonen's multi-media collaboration, The Tristan Project, has now evolved into a fully staged production for L'Opéra National de Paris. Provocative, luminescent and lavishly cast, it purports to offer two parallel readings of Tristan und Isolde.

First seen in Los Angeles in a series of concert performances, Peter Sellars, Bill Viola and Esa-Pekka Salonen's multi-media collaboration, The Tristan Project, has now evolved into a fully staged production for L'Opéra National de Paris. Provocative, luminescent and lavishly cast, it purports to offer two parallel readings of Tristan und Isolde.

Students of Viola's video art will recognise many of the images in Tristan. In common with the Nantes Triptych and Five Angels for the Millennium, there's a good deal of fire, a good deal of water, and some spectacular slow-motion submersions. Less predictable is the Platonic convergence of male and female souls during Isolde's Liebestod, the hand-held seascape, the real-time dawn sequence, and an extended diptych of a purification ritual that is, distractingly, enacted by the spitting images of the couple in the line-drawings to The Joy of Sex. The colours, throughout, are Marian blues and golds.

Whether beautiful or banal - and in just over four hours of music there is plenty of both - Viola's video dominates the dialogue like a premiership match on a pub television, confirming my opinion that moving images have a narcotic effect, regardless of their content. On face value, this is apposite: Tristan and Isolde are themselves intoxicated, disabled by the intensity of their desire to merge into one, and Wagner's score ensures that we share their sense of numinous abandon. But those who allow themselves to drift in Viola's pools of amniotic fluid will miss much by not attending to Sellars's disciplined direction of the text and James F Ingalls's taut, subtle lighting.

If Viola underlines the annihilation of individuality, Sellars and Ingalls underscore the lovers' separateness. With a simple dais as bed, boat and catafalque, and two rectangles of light that shift in size and shape, director and designer suggest parallel prisons of loneliness. Tristan (Ben Heppner), who in Sellars's backstory now carries the added burden of having been King Marke's lover too, stands in a narrow sentry-box of half-light, Isolde (Waltraud Meier) in a cavernous chamber of darkness. Their gestures are spare, their blanched hands made seemingly huge by Martin Pakledinaz's ascetic costumes, their movements infrequent, their companions - like their on-screen counterparts in Viola's Act I diptych - apparently alternative versions of themselves. Eye-contact between them is minimal, though when it happens, as with the kisses between Tristan and Isolde and Tristan and Marke, it has maximum impact.

The detail in Sellars's direction of Heppner and Meier is extraordinary, yet their faces are almost always only half-lit and their voices are the primary means of expression. Throughout the production, darkness is used to suggest privacy; be it the privacy of solitude or the privacy of chaste intimacy. The moments when that privacy is invaded are as pivotal as the moments of connection: the unruly sunrise in Act II, and the arrival in Cornwall at the close of Act I. With the horns and male chorus in the galleries of the vertiginous Bastille auditorium, Franz-Josef Selig's King Marke suddenly present in the centre of the stalls, Viola's screen a featureless band of corn-yellow, and the house lights abruptly raised, Tristan and Isolde are exposed in flagrante; psychologically if not physically.

Such unity of stage, screen and score is rare; occurring maybe three or four times. But with Salonen's measured, steady command of the score - a slower account than any I've heard before, but one that never sags - Sellars's assured management of the arc of each Act, and some superlative singing from what is very nearly a dream cast, Tristan is an almost overwhelming musical experience, regardless of the prosaic nature of some of Viola's imagery. Having thought Salonen a facile musician on previous hearings, I was astonished by the depth and confidence of his Wagner. The orchestral playing is of a very high quality, the cor anglais solo ravishing, the chording sound and true, the tone of the strings intensely shaded. Heppner's tortured, guilty, wordy Tristan is magnetic even through the longeurs of Act III, Meier's Isolde (surely one of her last) radiantly ageless, Franz-Josef Selig's King Marke tender and grave. As Brangäne, Yvonne Naef excels, Alexander Marco-Buhrmeister is an impactful Melot, the gravelly Jukka Rasilainen a thoughtful Kurwenal, and Toby Spence a stunning Shepherd and Young Sailor. I don't for one moment consider this to be a definitive production of Tristan, nor do I think that it will prove to be an equivalent technical watershed to Montalvo and Hervieu's multi-media Les Paladins, but gosh, what an audacious, impressive experiment.

Aside from a brief teenage obsession with Eight Songs for a Mad King, I've never considered myself a fan of Sir Peter Maxwell Davies's music. But the string quartets he has written over the last few years for the Maggini Quartet have been a revelation; demonstrating a lyricism and coherence he has not, to my mind, sustained in other idioms. Naxos Quartet no. 6, premiered on Tuesday at the Purcell Room, seamlessly wove together contemplative and ecstatic fragments of Advent and Christmas plainsong, trills of Ravelian sweetness and energy, allusions to the final accompanied recitative of the St Matthew Passion and a fiendish pizzicato Estampie. Like Britten and Tippett, Maxwell Davies is a natural in this genre. This is his finest quartet yet.

'Tristan und Isolde': Opéra Bastille (00 33 1 72 29 35 35), to Saturday

a.picard@independent.co.uk