Music theory is the study of the practices and possibilities of music. It generally derives from observation of, and involves hypothetical speculation about how musicians and composers make music. The term also describes the academic study and analysis of fundamental elements of music such as pitch, rhythm, harmony, and form, and refers to descriptions, concepts, or beliefs related to music. Because of the ever-expanding conception of what constitutes music (see Definition of music), a more inclusive definition could be that music theory is the consideration of any sonic phenomena, including silence, as it relates to music.