Britten's War Requiem Royal Festival Hall, London

"My subject is war, and the pity of war... the pity war distilled." So said Wilfred Owen. So said Benjamin Britten. And Krzysztof Penderecki. And out of that pity came sound and fury. For Penderecki, the "eight minutes and 37 seconds" of his Threnody to the Victims of Hiroshima were, one feels, an expression of shock and inadequacy - curt, ugly and somehow inappropriate, like a nervous laugh. Sound where there should be only silence. And a giddying array of sound. Strings bowed, plucked, scraped, slid in all manner of permutations. Threnody is like a parody of catastrophe. In the abstraction of its sounds, we seem to hear - we do hear - screaming, moaning, the expiration of countless thousands. If you could put a face on it, you'd see only contortion.

But I'm expressing the inexpressible, I'm making explicit that which is best left implicit, putting images into your heads, telling you what to think and feel. Isn't that what Stravinsky accused Britten of doing in his War Requiem? Well, pace Stravinsky. Sir Simon Rattle brought both works to the South Bank on Wednesday night and their grip on a large audience was so tangible it was almost uncomfortable. The Penderecki is uncomfortable, of course. In a sense, this is music beyond emotion, beyond all recognisable human feeling. The Britten is anything but, and that, one imagines, is what jarred on Stravinsky. It is overt, it is theatrical (when was Britten not?), but who with ears and a heart can listen to his juxtaposition of the "Lacrimosa" and Owen's poem "Move him into the sun" - the two alternating with increasing urgency until they are but one utterance - and not feel that he has, in some extraordinary way, crossed all barriers of language and culture. War Requiem excites rather than incites anger. It protests its compassion. It is a masterpiece, and there's an end to it.

Rattle began by fighting a losing battle with the Festival Hall acoustic. The eddying chants of "Requiem aeternam", seemingly muttered at random across the ages, were robbed of their mysterious, somewhat indistinct character and cast - the effect of distant voices only gradually coming into focus. The dryness of this hall seriously compromises atmosphere in a work such as this, a work whose spatial planes of sound are an intrinsic part of its effect. It took a while for Rattle to get beyond that. The echoing and re-echoing fanfares, the seismic drum upheavals of the "Dies Irae" created no appreciable aftershocks, no resonance. Everything was cut to the bone. Not least the small but perfectly formed City of Birmingham Chorus whose precision - keen, incisive, quick of reflex - was just as well in the circumstances. Of course I should like to have heard less of their multitudinous "pleni sunt ceolis" in the "Sanctus" (the blurring of this rising tide of excited voices is all part of the effect - and what an effect with its flaring brass hosannas), but in the supplicant harmonies of the unaccompanied refrain which serves as a benediction for all three parts of the mass, they were one faith, one voice, landing to perfection on the final chord of the cadence each and every time.

The two soldiers whose "Strange Meeting" brings the work to such a humbling conclusion were Robert Tear and Simon Keenlyside, the former in some vocal distress now, less able to sustain those haunting ascents into the ethereal (the closing "dona nobis pacem" of the "Agnus Dei" was one such moment of truth), the latter a fresh young voice content to dignify rather than to dramatise Owen's salutary words. And perhaps that lent his contribution a less personal tone than those of us brought up on Fischer-Dieskau have come to expect. Not that there wasn't a sense of private communication. Britten's attentive chamber orchestra (adept CBSO principals characterising everything from "shrill, demented shells" to angelic voices) sees to that, pulling focus on these masterful settings in such ways as to have you reaching for the score to see exactly how he achieves this or that effect, this or that insight. In the broader orchestral and choral plane beyond, Andrea Gruber was the excellent soprano, the voice of pity, compassion, consolation, the voice "seized with fear" (and how) in the headlong stampede to the shattering climax of the "Libera me". Rattle went for that - the mother of all G minor chords - like it were the portent of every holocaust every catastrophe, real or imagined.