Clock Tower 3 Original Soundtrack
Fantaisie-Impromptu is a song from Clock Tower 3 on the Clock Tower 3 Original Soundtrack. It plays straight before Alyssa Hamilton is transported back in time to London, circa World War II, and while she explores the ruined city.
It is featured as the Pocket Watch melody.
It also plays on the piano in Ashley Tate's room in Clock Tower II: The Struggle Within, which is likely what inspired it to appear in Clock Tower 3.