Yes, and also dreams: “For the Middle Ages, however, absorbed in the lessons of the Biblical tradition and of antiquity, dreams and a general concern with the visionary were much closer to the heart of things.”
"were far from unimportant in the search for ‘spiritual’ answers to existence. The roll of honour of auctoritates on this topic is impressive: Aristotle, Virgil, Cicero, Macrobius, on the one hand; the Bible, Augustine, Albertus Magnus, Thomas Aquinas, on the other. "
Symphony No. 8 “Unfinished” by Franz Schubert - Schubert allegedly had a dream in which he heard the opening themes of this symphony, which he then worked into the two-movement piece.