Unresolved leading tone · Rules
The leading tone (the note a semitone below the tonic) rises by semitone to the tonic when the next chord contains it, in any voice. If the next chord does not contain the tonic, it is not required.
- Unresolved leading tone: The leading tone (the note a semitone below the tonic) rises by semitone to the tonic when the next chord contains it, in any voice. If the next chord does not contain the tonic, it is not required. (Piston, ch. 3, pp. 32–33 and 35)