The song XXX was by whom?
Parsifal
According to his own account, recorded in his autobiography Mein Leben, Wagner conceived Parsifal on Good Friday morning, April 1857, in the Asyl (German: ``Asylum''), the small cottage on Otto Wesendonck's estate in the Zürich suburb of Enge, which Wesendonck - a wealthy silk merchant and generous patron of the arts - had placed at Wagner's disposal, through the good offices of his wife Mathilde Wesendonck.