(Photo: © Wiener Staatsoper / Michael Pöhn) Before I get to the performance in question for this review, “Dialogues des Carmelites,” I have a few words about the setting. Though reasonably well-travelled, somehow I never went to Vienna. I did attend Salzburg for the festival. And Munich as well, for a shattering Janacek’s “From the House of the Dead”. Paris, {…}