音樂理論
Music theory is frequently concerned with describing how musicians and composers make music, including tuning systems and composition methods among other topics. 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 they relate to music. This is not an absolute guideline; for example, the study of "music" in the "Quadrivium" liberal arts university curriculum that was common in medieval Europe was an abstract system of proportions that was carefully studied at a distance from actual musical practice. However, this medieval discipline became the basis for tuning systems in later centuries, and it is generally included in modern scholarship on the history of music theory.