What does the term "supertonic" refer to in music theory?

The term "supertonic" specifically refers to the second tone of a major or minor scale. In the context of Western music theory, scales are typically numbered according to their degrees, with the tonic being the first degree. The supertonic is one interval above the tonic, hence its name, which is derived from Latin, meaning "above the tonic."

In the context of a major scale, the supertonic plays an important role as it often functions as the basis for the ii chord (the supertonic chord), which is a minor chord in a major scale. Similarly, in a natural minor scale, the supertonic corresponds to the minor chord built on that degree. Understanding the function of the supertonic helps to comprehend chord progressions and the overall structure within compositions, highlighting its importance in musical analysis and composition.