The Sonatas and Interludes are Cage´s masterwork for Prepared Piano. In the Composition Cage expresses his interpretation of the permanent emotions of Indian tradion: The Herois, the Erotic, the Wondrous, the Comic, Sorrow, Fear, Anger, the Odious(the four dark moods) and their common tendency toward tranquility.It was Cage first composition using Hindu philosophy and he composed the Sonatas and Interludes in a period of reading the works of the Indian art historian and critic Ananda K. Coomaraswamy.