Common-tone harmony connects chords by keeping one or more notes in place as the other notes move. The shared tones act like a thread between chords, even when their roots or functions differ.
This is especially useful for smooth voice leading: keep a shared note in the same register, then move the other voices by the smallest practical distance.
Spot the shared notes
C major and A minor share C and E. When the chords change, those notes can stay while only G moves to A.
Try it
- Pick two chords and write their note names, not just their roots.
- Circle the common tones and keep them in the same octave.
- Move the remaining notes as little as possible, then listen for a smoother transition.
Key takeaway
A shared note gives the ear continuity. Use it as an anchor while the other voices create the change in harmony.