It’s August 26, 1995. At Reading Festival, festival booker Neil Pengelly heads backstage at the Melody Maker Stage to find Russell Warby, the booking agent for the band that’s about to go on and play their first ever UK festival show.

“Come and look at this,” he says and, without another word, leads Warby to the stage. The scene before him reveals a heaving tent, with screaming fans crowdsurfing, climbing the tentpoles and hurtling over the barrier with enthusiasm.

“And ...