The rising dust clouds can mean only one thing. Foals have hit Reading. They’ve only been on site a couple of hours, but Yannis Philippakis looks like he’s been here since Thursday. When the frontman prowls the lip of the stage after ‘My Number’, which opens this hastily announced secret set, bright white lights catch his face and you notice his black curls are matted and his beard is straggly. There might be a hint of a hangover in his eyes too.

Then, when he holds his guitar against his torso like a shotgun and surveys the glistening faces before him, you see his pecs flex. During ‘Mountain At My Gates’, he beats his chest and claws at his tight white t-shirt. He looks, frankly, like a beast – even more than guy in the front row wearing a horse mask – and you sense chaos.

‘Inhaler’ turns over like a motorbike engine, Jimmy Smith riding its greasy riff like a Hell’s Angel as Jack Bevan and Edwin Congreave weave drumbeats and synth parts together. Its breakdown – before which Bevan stands on his stool and bashes his sticks together – feels like A Moment. The din of the crowd melts into its riff, and when they ignite the last chorus, Yannis reaches peak Tarzan, screaming ”UHHH UHHH UHHH/ Impossible, possible way!!!” like a tribesman lost in the undergrowth, desperate to make himself heard. Although it’s far quieter, ‘Spanish Sahara’ feels just as primal, with the crowd impatient for the drop from the moment they hear Yannis go, ”So I walked into the haze…” They draw out every second of its six glacial minutes. When ‘Red Socks Pugie’ – dug out from ‘Antidotes’ and the days when an African-inspired melody and clean guitar riff were enough for Foals – follows, it feels like a real surprise. Naturally, it sounds far muckier than back in 2008, but still it can’t contain Foals’ increasing heaviness.

‘What Went Down’ can. For the five minutes they play it, it’s the only thing on site beastlier than the man singing it. Screaming doesn’t cover the noise he summons in the chorus. When he makes the inevitable descent into the crowd at the end, you feel that they’re clawing at him not just because he’s a maniac frontman, but because he looks and smells just like them.

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