In music, a discipline involving the construction of cognitive systems to be used as a tool for comprehending musical compositions.

The discipline is subdivided into what can be called speculative and analytic theory.

Speculative theory engages in reconciling with music certain philosophical observations of man and nature.

It can be prescriptive when it imposes these extramusical contentions to establish an aesthetic norm.

In more general usage, the term musical theory is used to include the study of acoustics, harmony, and ear training.