Godspeed You! Black Emperor – Brixton Academy, London, 21/11/13

It starts with a drone. Twenty minutes of drone, the house lights dimmed and the stage glowing red and everyone – everyone – around me putting earplugs into their ears. For a moment I worry that maybe I should be doing the same – that maybe I should have thought about this a little earlier, given that Godspeed You! Black Emperor’s propensity for volume is pretty much their defining trait – and then I remember that any hearing I had left was obliterated by the support act.

Ah yes – the support act. For most bands being slightly feverish and half-wracked with flu would detract from the live experience: for New York’s Pharmakon it’s pretty much the ideal state. For half an hour Margaret Chardiet charms the Academy with her self-proclaimed power electronics/death industrial tunes, if that’s the right word for a nail bomb collage of machine noise and shrieking rage. It’s not a performance so much as an exorcism, draining and atonal and yet weirdly compulsive – although it’s hard to discern quite where the speaker output ends and the tinnitus kicks in.

True, it’s not for everyone. “What the hell?” exclaims one girl standing nearby. “My girlfriend’s seeing Sigur Rós at Wembley,” says someone else. “Maybe I should have gone with her.”

Quite a few people mention Sigur Rós, actually, particularly during Godspeed’s opening drone – and granted, there are a fair few parallels in the expansiveness of both bands’ sound, in the ebb and swell and space within their songs. But the Icelandic three-piece have a baptismal quality that’s pretty far from Godspeed’s nightmare, from their sociopathic build from lone violin to maelstrom of noise, and whilst the former thrive upon performance the latter seem indifferent to it.

Indeed, with the lighting static and the auditorium black, the eight-piece play pretty much within a circle, their guitarists seated with their backs to the audience, it’s a set that at times feels voyeuristic, as though we’re staring en-masse into a practice session or an intimate gathering of friends. There’s no interaction from any member, no acknowledgement of the 3,000 or so faces fixed upon them and little attempt to fulfil any of the usual tenets of a live show – engage the crowd, make them feel a part – but none of this matters. This is a band that can captivate through sheer sound alone.

Oh sure, there’s the projections – vast backdrops of train journeys and war crimes, of melting objects and stock exchange tickers, the awful and the mundane looped and cut and juxtaposed by twin projectors forging narrative from chaos. They make for a fittingly dystopic accompaniment, even if after a while many of those standing nearby opt to close their eyes and focus on the music.

It deserves their attention. From “Mladic’s” slow descent from mournful strings to frantic riffs through to closer “The Sad Mafioso’s” cinematic sweep theirs is a masterclass in controlled restraint, in tension and release, with every note laden with portent and power. It’s rare for the Academy to be this silent, this expectant: for one hundred minutes our bodies are still but the air crackles with energy, with weight and poise and grace and beauty and ugly, bruised ferocity – and when it’s over few move or even speak until the house lights come up and the crew start clearing the stage.

Later, on the train, people are struggling to process what they just saw. ‘That was…’ starts one guy to his friend, and then gives up. The friend just nods and looks away and the carriage falls to silence.