“This is the tale of two city operas, both of which present high art at popular prices. That innate contradiction has landed them in trouble, but where English National Opera in London has turned around its fortunes in the past year to enjoy acclaim, New York City Opera faces a rump season that may be its last. Yet such is City Opera’s insularity these days that it seems to have learned nothing from ENO’s near collapse. Let’s see if we can help.”