Answer
Bluebeard's Castle is a famous opera by Béla Bartók, a Hungarian composer known for his innovative use of folk music and complex rhythms. The opera, which premiered in 1918, is based on the folk tale of Bluebeard and tells the story of a young woman who marries the mysterious Bluebeard and discovers his dark secret. The opera is known for its haunting melodies, evocative harmonies, and powerful orchestration.