I seem to have been steeped in opera lately. First there was Ariadne auf Naxos at Glyndebourne, then Peter Grimes on the beach at Aldeburgh, and now Wagner’s complete Ring cycle at Longborough in Gloucestershire, all within the space of three weeks. As I write, I haven’t quite seen the whole Ring cycle — there is still one more opera, Götterdämmerung, to come — but it is already plain that something astonishing has happened.