In music, what does the term "leading tone" refer to?

The term "leading tone" refers to the seventh degree of a scale, which has the inherent tendency to resolve upward to the tonic (the first note of the scale). This note, when considering the context of a major scale, is a half step below the tonic, creating a strong pull to it.

In tonal music, the leading tone plays a crucial role in establishing key and facilitating harmonic movement, as it encourages resolution into the tonic. This musical relationship is fundamental to how melodies and harmonies are constructed, creating expectation and anticipation in the listener.

While the other options relate to different musical functions or scale degrees, they do not capture the specific characteristics of the leading tone, which is defined by its position relative to the tonic and its resolution tendency.