If summer opera is any kind of a ­barometer of economic health – and it could after all be handy for gauging the mood of hedge-fund managers and other plutocrats – then we are in quite a period of retrenchment. The schedules are majoring pretty heavily in the hard-times fallbacks of Mozart, Rossini, Verdi and Puccini, with a few extra old chestnuts in the fire. What with the conservatism of the art form as a whole, and of its bubbles-and-strawberries avatar in particular, it does not always make for the most dramatically riveting experience, though musical standards tend to be uniformly excellent.So good on Grange Park for bucking the feel-good trend with Benjamin Britten’s miserablist Peter Grimes of 1945 – a bold choice for many reasons (English, twentieth ce