If you have to consult the Reddit thread ‘am I too old for Coachella?’, then the answer is probably ‘yes’This morning, over breakfast, in the course of discussing the week’s news, I happened to say the word “Coachella” in front of my two scornful 11-year-olds, whose heads snapped up from their screens in unison. “How have you heard of Coachella?” said one in amazement. “How have you heard of Coachella?” I replied. They exchanged a look with which I’ve become increasingly familiar – namely, the “here we go” look reserved by the very young for the very middle-aged. “What is Coachella, then?” I said, to which they replied: “It’s where influencers go.”This is, of course, an accurate summary of what the California music and arts festival has become in the 27 years since its inception, but that’s not why I bring it up. The festival, which is running this week, has featured by Jack White, FKA Twigs and Sabrina Carpenter, but most of the publicity has gone on the audience; specifically, on the...