Question: In what year was the mother of Manon Gropius born?
Sentence (from "In Memory Of ... (ballet)"): In Memory of ... is a ballet in one act made by New York City Ballet ballet master Jerome Robbins to Berg's "Violin Concerto (to the Memory of an Angel)" of 1935 (written on the death of Manon Gropius, daughter of Alma Mahler, Gustav Mahler's widow, and Walter Gropius), based on themes from Mahler, a Carpathian folk song, and Bach's "O Ewigkeit, du Donnerwort", BWV 20.
Relevant evidence: Yes