We went last night to Tristan and Isolde, the final performance of Grange Park Opera at the Grange, before they move to a brand new grand opera house at West Horsley Place, outside Guildford and closer to London (phew !).   According to Simon Freakley, the chairman, who stood on stage before the performance, they have had 50 productions over 18 years.   Now, their lease has been terminated.   It was in some ways a sad occasion, standing on the terrace of William Wilkins’s great Greek Revival house, built for Henry Drummond in Roman cement in 1804, just after Wilkins had returned from three years travel in Greece and Asia Minor.   But Tristan and Isolde was more tragic:-