Frank Carter & The Rattlesnakes have announced a surprise last minute set at Reading Festival 2021 this evening (Friday August 17).Things kicked off at the twin Reading & Leeds sites today, with the southern edition of the event seeing huge sets from the likes of Inhaler and Sports Team before AJ Tracey, Sam Fender, Catfish & The Bottlemen and Stormzy close proceedings tonight.Now, UK punks Frank Carter & The Rattlesnakes have confirmed news of a secret set on The Lock Up Stage at 6.05pm in