In December, the Vienna State Opera opens a second house, called NEST (short for “Neue Staatsoper” or New State Opera). Located on Karlsplatz—a stone’s throw from the main house, and even closer to the storied Musikverein—the facility caters to children, teenagers, young adults, and families. Though tiny (capacity: 248), NEST is outfitted with all the accoutrements the full-fledged operatic experience requires, including an orchestra pit and a fly system. The 100-odd events of the inaugural season run from quiz shows, talks, workshops, and, of course, new operas and ballets geared to young audiences. Happily, the city’s conservatories and academies will have a showcase here, as well. The marquee attraction of the opening weeks is an immersive, interactive postlude to Götterdämmerung, the final chapter of Wagner’s “Ring” cycle, developed by the experimental theater collective Nestervals. The postapocalyptic fantasia catapults viewers into an Austria of the future. “The world in its previous order is finally history,” we are told. “The world population has fallen below one billion due to climate catastrophes. Life without the internet, without globalization, and almost without electricity has begun.” Snatches of Wagner mix with snatches of new music, and audiences follow the action from the cellar to the dome, all through the auditorium as well as backstage. Our advice: wear sneakers. —Matthew Gurewitsch