Leading-tone followed by tonic
Note
Seventh scale degree (or lower leading tone)
Typically, when people speak of the leading tone, they mean the seventh scale degree () of the major scale, which has a strong affinity for and leads melodically to the tonic. It is sung as ti in movable-do solfège. For example, in the C major scale, the leading note is the note B.As a diatonic function, the leading tone is the seventh scale degree of any diatonic scale when the distance between it and the tonic is a single semitone. In diatonic scales in which there is a whole tone between the seventh scale degree and the tonic, such as the Mixolydian mode, the seventh degree is called the subtonic. However, in modes without a leading tone, such as Dorian and Mixolydian, a raised seventh is often featured during cadences, such as in the harmonic minor scale.
A leading tone outside of the current scale is called a secondary leading-tone, leading to a secondary tonic. It functions to briefly tonicize a scale tone (usually the 5th degree) as part of a secondary dominant chord. In the second measure of Beethoven's Waldstein Sonata (shown below), the F♯'s function as secondary leading-tones, which resolve to G in the next measure.