Harmony
Modulation: How a Key Change Is Confirmed
A modulation is not a chromatic chord; it is a new key confirmed by cadence. The routes into one, and how to read them off the page.
Modulation
A change of tonal centre in which the music settles into a new key with its own tonic and cadence, often through a pivot chord.
Also called: Key change, Changing key
Modulation is a change of tonal centre, in which the music settles into a new key with its own tonic and cadence. A modulation from C major to G major can be made through the pivot chord A minor, which is vi in C and ii in G. After the pivot, a dominant of G, such as D7, leads to a G major cadence, and the new key is established. Modulation differs from tonicisation, where a passage briefly treats another chord as a tonic and then returns. Modulations are also made through a common tone or a chromatic change. The most common modulations in tonal music go to the dominant or the relative key, the closest related keys. Many Classical movements modulate to the dominant in their exposition.
Related terms
- Pivot chordA chord that belongs to both the old key and the new one, used as the hinge of a modulation because its function changes between them.
- TonicisationA brief passage that makes a chord other than the tonic sound like a temporary home, usually through a secondary dominant, without a full key change.
- Secondary dominantA dominant chord that tonicises a diatonic chord other than the tonic, written with a slash such as V7/V, which is D7 in C major.
- Modal mixtureThe use of chords or scale degrees from the parallel mode within a passage, usually minor material in a major key, to add colour.
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Fundamentals
Relative and Parallel Keys Explained: Major and Minor Partners
A major key has two close minor partners. The relative minor shares its key signature, the parallel minor shares its tonic, and each pair connects keys in a different way.