Let the shouting commence! The Shangri-Hell protest movement occupies the John Peel stage for an afternoon, dispatching its angriest barricade breachers to loudhail the Truth at the media-brainwashed hordes waiting for Years & Years.

First up, Kent’s Slaves take a semi-comic tack on social observation, slipping the odd comment about melting ice-caps into songs largely about wage-slave misery (Cheer Up London), keeping large fish (Feed the Mantaray) and running from the Tunbridge Wells Bigfoot (Where’s Your Car Debbie?). They make a compulsive pair: guitarist Laurie Vincent spews disco punk and Iggy-inflected Pistols blues while singing drummer Isaac Holman – shaved chest bared beneath his flapping open shirt, like a man trying to have a pub fight with himself – recites between-song street poetry in the style of an illegitimate son of Ian Dury and Chas Smash and bashes his drum set like the drunk bloke who eventually ruins every Sacred Space drum circle. They thrill the crowd with their slapstick fun punk, but you wonder how long the novelty can last, particularly when a crowd-surfing manta ray invades the stage.

Sleaford Mods certainly seem to be experiencing the diminishing returns of shouting for a living. “Are there a lot of people in the toilet or something?” barks Jason Williamson, sensing the hype spotlight shifting elsewhere, but the half tent that sticks around gets the Mods at their most vitriolic. For the uninitiated, they comprise one bloke (Andrew Fearn) who presses play on some laptop Batman beats and then just stands there swigging lager, and a second bloke (Williamson) who rants very sweary and often incomprehensible social and cultural grievances like Mark E Smith going berserk in a post office, while manically batting invisible flies from his ears. Every song ends with a furious final slogan – “Smash the fucking window!”, “Sack the manager!” – or a lusty raspberry, and involves a torrent of abuse hurled at everyone from patronising middle managers to Johnny Borrell. When there isn’t a clear thematic thread à la Jobseeker, they have you furiously googling their lyrics to discover exactly what Williamson has against Spit the Dog and the “fucking Shredded Wheat Kellogg’s cunts!” Needless to say, if you’re wondering what the snatched reference to Shoreditch in A Little Ditty might be about, it’s safe to assume he’s not being complimentary about the area’s generous selection of jam-jar cocktails.

Yet as Williamson berates his microphone on the topics of unsavoury toilets, detailed sex parties and deadly tarantula cargos, the rapturous reception suggests that aggrowave may yet catch on. Otherwise, the cult fate of Bristol’s the Pop Group awaits: a few hundred devotees grooving dutifully to your evil proto-Duran Duran funk and corrupted disco. Yet despite singer Mark Stewart occasionally screaming like the most sarcastic Florence Welch impression imaginable, their politics come across clearest, be it via the yowls of “We are all prostitutes!” and “Hypocrites!” during the anti-consumerist We Are All Prostitutes or the highly pertinent Citizen Zombie. Somewhere on site, Billy Bragg’s value set must be burning …