Remember Our Town? Remember Emily Gibbs, née Webb, who dies too young and goes back for another look at the life of the living? In Guercœur, a mystical tapestry by “the French Bruckner” Albéric Magnard (1865–1914), a slain medieval kinglet goes back to the nether world to save his people, which is admittedly a somewhat different errand. It doesn’t go well. For one thing, his best friend and his wife are now lovers. For another, he is slain for a second time. Back on the Far Side, the Goddess of Truth comforts him with assurances that humankind is approaching the threshold of something wonderful. The riveting French baritone Stéphane Dégout takes the otherworldly title role, paced in Strasbourg by Ingo Metzmacher, a tireless champion of unsung eccentrics. (The second phase of the run, in Mulhouse, is under the baton of Anthony Fournier.) —Matthew Gurewitsch