The xx, Brixton Academy, London

For all the talk of The xx’s coy, stripped-back simplicity, they deliver an unremitting, aggressive live show. There are times at the O2 Academy in Brixton tonight when the gig almost descends into a Berlin warehouse techno rave. Clad all in black, the trio take to the stage behind a screen depicting what looks like coagulating mercury. It is all very xx – sleek, sexy, monochrome, smoke, strobes. But once opener ‘Angels’ is done and the fabric screen drops to reveal the band, it is only a matter of songs before the hushed vocals and ethereal guitars make way for Jamie Smith’s devastating percussion trickery.

Smith’s production influence on the band is increasingly apparent on ‘Coexist’, their second album, and even more so live. Sexy and slender (the xx are all about assonance), Romy Madley Croft and Oliver Sim slink about the stage – the latter resembling a Tim Burton Dracula character. They don’t command a huge stage presence but the sound is crisp and clean and their vocals leave even the hardiest punter weak at the knees. But it is Smith who steals the show. He pounds out bass kicks from his “drum kit” which stretches the width of the stage. Not as evident on the album, the percussion is the driving force of the music and Smith takes full advantage of this in a live environment. At times it is just like watching a DJ – the spotlight on Smith centre stage as he stoops over a mixer and sample pad, twisting knobs, elbows pointedly raised, bouncing to hi-hat drops. Croft and Sim play second fiddle to the pulsating backdrop, but to perfect effect. This is exemplary when Smith mixes out of ‘Swept Away’ in to ‘Shelter’ with the intensity of four-to-the-floor techno – Shelter is transformed into a different entity from the beautiful but cowering track on the album. It becomes a club track.

Again and again, Smith has the building’s foundation shaking. None more so than the bass drop on ‘Fantasy’, which snatches gasps from the crowd. Few songs are as they are on the albums yet all is tight and careful: ‘Infinity”s “I can’t give it up” breakdown is amplified into a soaring crescendo; ‘Stars’, to finish, is slowed down, sped up, then slowed down, its beauty enhanced; and the licks of ‘Crystalised’ make way for a much more bass-heavy accompaniment.

Whenever Croft and Sim make their way to the front of the stage to address the crowd they are drowned out by cheers and applause, something which clearly means a lot to them: Brixton is where the three of them enjoyed their first gigs. It is a homecoming of sparse but concentrated moments of emotion coupled with the expected elegance and ingenuity of The xx and a captivating light show, giant X stagedrop and heavy-duty delicacy.