No question, the Royal Opera is on a roll. Just look at the cast list alone for Deborah Warner’s new production of Britten’s Peter Grimes. Allan Clayton sings Grimes, Bryn Terfel is Captain Balstrode, and John Tomlinson is Swallow, with Mark Elder conducting. Even before you get to a supporting cast that includes premium names such as James Gilchrist, Jennifer France and Catherine Wyn-Rogers, you’ve basically got the three pre-eminent British male singers of their respective generations, singing their boots off in the greatest of all British operas under the baton of the conductor who (it’s naive, but let’s dream)...