Wagner’s operas are often heard in a harsh, hectoring style derisively known as the “Bayreuth bark.” Yet Wagner’s vocal ideal was Italianate. The Bayreuth Festival, which he inaugurated in 1876, sometimes goes out of its way to find singers who can deliver that long cantabile line. Too bad Roberto Alagna canceled his first Lohengrin there several seasons back. This year, management cast the Maltese tenor Joseph Calleja as Parsifal, the holy fool who redeems a sacred relic lost to an evil wizard—and in so doing redeems the world. A seductive idea: Calleja’s burly yet supple instrument is arguably the sexiest in the business (resist him, if you can, as the playboy Duke of Mantua in Rigoletto). But a persistent throat infection has forced him to withdraw. His Austrian colleague Andreas Schager, a familiar quantity in this role on this stage, steps into the breach. Happily, though hardly Italianate, Schager is no barker, either. The new production is directed by the American technocrat Jay Scheib, a professor of theater at MIT. For the Full Monty, viewers will need individually fitted augmented-reality glasses, but fewer than half the audience will get to wear them. The premiere will stream live and remains available through New Year’s Eve. —Matthew Gurewitsch