A fugue is a type of musical composition characterized by the systematic repetition of a main theme, called the subject. This theme is introduced by one voice or instrument and then imitated by others in a structured manner. Fugues often feature multiple voices, creating a rich tapestry of sound as each part weaves in and out of the main theme. Fugues are commonly found in classical music, particularly in the works of composers like Johann Sebastian Bach. They can vary in complexity, with some featuring intricate counterpoint, where different melodies interact harmoniously. The form is known for its intellectual depth and emotional expressiveness, making it a significant element of Western music tradition.