Why Look for Common Tones When Changing Chords?

Adult pianists often treat each chord as a hand shape that must be aimed at again: lift the old shape, then place the new one. The notes may be correct, yet the change can feel tense and disconnected, while three voices are heard as a single block. Common tones offer another entry point. First identify which notes remain the same between the two chords, then decide where the other voices need to go.

Take a right-hand C major triad, C–E–G, moving to an A minor triad voiced C–E–A. C and E can remain in place while only G moves up to A; the left-hand bass can then move from C to A. “Remaining” is primarily an aural and physical relationship, not a demand to hold the keys continuously. If the phrase requires a change of finger, a fresh attack or a different touch, a common tone may be released and played again. What matters is that the ear hears it as a continuing voice rather than an isolated key that must be found anew.

This reflects a familiar principle of voice leading in common-practice harmony: retain shared tones where appropriate and move the other voices to nearby suitable notes. It is not a shortest-route rule for every kind of music. Melody, rhythm, colour or deliberately parallel chords may require larger movements. The point of practising common tones is therefore not merely to move the hand a few centimetres less. It shifts attention from “grabbing the next chord” to hearing how each line continues. The movement becomes more economical because the musical direction is clearer.

https://musictheory.pugetsound.edu/mt21c/VoiceLeading.html

If you use <a href="https://apps.apple.com/us/app/scoreflow/id6796205656">ScoreFlow</a&gt; to organise practice, take a short passage with successive chords and make “hear the common tones first, then move the remaining voices” the single focus of that session.