Piano theory refers to the fundamental concepts and principles that govern how music is created and understood on the piano. It includes understanding notes, scales, chords, and rhythm, which are essential for playing and composing music. Learning these elements helps pianists interpret sheet music and develop their musical skills. Additionally, piano theory encompasses the study of harmony and melody, which are crucial for creating pleasing sounds. By grasping these concepts, musicians can improve their improvisation and composition abilities, making it easier to express their creativity on the piano.