Yannick Nézet-Séguin leads the classic John Dexter production of Poulenc’s devastating story of faith and martyrdom. Mezzo-soprano Isabel Leonard sings the touching role of Blanche and soprano Karita Mattila, a legend in her own time, returns to the Met as the Prioress. World Premiere: Teatro alla Scala, Milan, 1957. One of the most successful operas of the later decades of the 20th century, Dialogues des Carmélites is a rare case of a modern work that is equally esteemed by audiences and experts. The opera focuses on a young member of an order of Carmelite nuns, the aristocratic Blanche de la Force, who must overcome a pathological timidity in order to answer her life’s calling. The score reflects key aspects of its composer’s personality: Francis Poulenc was an urbane Parisian with a profound mystical dimension, and the opera addresses both the characters’ internal lives and their external realities.