Harmony & motion
A chord name compresses several sounding notes into one label. Composition needs the fuller object: chord shape, bass, register, voicing, metric position and what came before.
voicing = root + chord shape + octave placement0 3 7 identifies a minor shape. 48 55 63 and 48 51 55 share pitch classes but produce different spacing and motion.Chord identity is not voicing
| Layer | What remains meaningful? | Can change independently? |
|---|---|---|
| Chord shape | Intervals relative to a chord root | Quality and extensions |
| Bass | Lowest structural pitch | Root position or inversion |
| Voicing | Actual pitch and register of every voice | Spacing, doubling and voice crossing |
| Function | Learned expectation in the present context | Meter, phrase, style and tonal center |
Preserve identity with close motion
4/4 · C minor · middle of phraseΣ motion = 10→0 · 3→3 · 7→8- Hear
- G rises by one semitone while C and E♭ remain common.
- Use
- Change harmony without making the texture sound like it jumped register.
- Why it fits
- The target A♭/C keeps two common tones and costs only one semitone of total voice motion.
How Build constructs the Chords layer
Build stores a chord as simultaneous relative collection degrees such as [0, 2, 4]. Its approaches then change one of four relations: onset placement, held common tones, voice displacement or spacing. A labelled tradition projection does not automatically inherit this tertian grammar; the Chords tab appears only when the selected collection declares that capability.
| Approach family | Operation | Listen for |
|---|---|---|
| Close motion | arg min Σ|vⱼ(t+1) − vⱼ(t)| | Few voices need to move. |
| Common-tone / pedal | keep one or more vⱼ invariant | Continuity inside change. |
| Stabs | place a voicing at selected cycle indices | Harmony becomes rhythm. |
| Release | depart from and return to a contextual centre | A directed arrival, not a universal law. |
Make phrase position strengthen resolution
4/4 · C minor · final strong beat11 → 12- Hear
- The leading tone rises to C while G remains common.
- Use
- Close a phrase more clearly than the same change on a weak subdivision.
- Why it fits
- Short voice motion, a common tone and learned dominant–tonic grammar align at a boundary.
Potential is conditional
A note or chord does not carry one permanent destination. Candidate continuations are ranked relative to the current voicing, metric position, phrase state, collection, tonal center, recent history and stylistic prior.
P(B | A, t, phrase, context)∝short motionvoice leading+common tonesidentity+metric roleposition+learned grammarsoft priorrank several next movesA high score means “supported by this model in this context,” not “the only correct continuation.” Explicit borrowing and modulation remain available.Terms, relations and sources
Key terms
voicingvoice leadingpotentialRelated chapters
Melody & phraseForm & arrangementDetailed lookup
Chord shapesProgression potentialNotation legendEvidence
Editorial sourcesModels state their boundary; tradition-specific claims require specialist sources.