Question: When did Frédéric Boulanger's wife die?
Sentence (from "Frédéric Boulanger"): He was the father of Ernest Boulanger, a composer of comic operas, husband to mezzo-soprano Marie-Julie Halligner of the Théâtre de l'Opéra-Comique and grandfather to Nadia Boulanger and Lili Boulanger.
Relevant evidence: Yes