Irish rap trio Kneecap took aim at UK Prime Minister Keir Starmer during a defiant performance Saturday at Britain's Glastonbury festival, which also saw Britpop legends Pulp wow fans with a surprise show.But Glastonbury organisers defied Starmer who had said it was not "appropriate" for Kneecap to perform at Glastonbury, one of the country's biggest and most famous music festivals.