“Look at my arse!” Three songs into Alt-J’s Reading Festival set, a man in a straw hat runs through the crowd, shouting and pointing at his bare backside. The image is in stark contrast with the four men onstage, clad in uniform black and positioned – bar drummer Thom Green – stock still behind their instruments. The trio, onstage with live bassist Cameron Knight, are halfway through ‘Something Good’, one of the smoother cuts from their Mercury-winning debut ‘An Awesome Wave’. Its gentle melody is hardly the sort of thing to prompt people to strip, but here, as night falls on Friday at Reading, everything Alt-J do incites mania.
Playing before headliners Mumford & Sons, they transform the slow, quiet undulations of their records into a series of fuzzy, improbably heavy bass drops. It’s done with high-pitched keyboard parts that summon the spirit of ‘90s house and some manic drumming from Green. In response, the crowd alternate between clambering onto each other’s shoulders, chucking their drinks, falling over and slurring Joe Newman’s lyrics – which are sung, as ever, quietly and into his chest. Sure, the hits are there – a souped up ‘Hunger Of The Pine’, a funked-up ‘Left Hand Free’, a slow and creepy ‘Matilda’ – but this is a set to be swallowed whole, with a neon light show to match the blurry noise spewing from the stage.
Their somewhat wooden presence means Newman and keyboardist Gus Unger-Hamilton aren’t much to look at, so they make up for it by bathing themselves in lasers and projecting pixelated TV static onto the images of their faces that intermittently fill the big screens. Combined with the glitchiness of songs like ‘Every Other Freckle’ and ‘Tessellate’, which hinges on a keyboard line from Unger-Hamilton that sounds transported from a Berlin sweatbox club, the effect feels primal. Drummer Green is more engaging, thwacking away at his kit dressed in fingerless gloves and a baseball cap, he looks like a personal trainer who forgot to get changed.
It peaks with ‘Nara’, which feels less a song and more a patchwork of Newman’s alien vocals and random blasts of bass from Green’s drum pads. It lasts for what feels like an eternity, and closer ‘Breezeblocks’ makes a dreamy conclusion. Alt-J’s fans walk away, not chanting their favourite songs, but dazed by the sheer mechanical power of what they’ve just witnessed.