Harmony
Secondary Dominants and How Tonicization Works
A secondary dominant makes any chord a temporary tonic. How to spell one, where it turns up, and what cancels the effect.
Tonicisation
A 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.
Also called: Tonicization, Local tonic
Tonicisation is the momentary treatment of a chord other than the tonic as if it were the tonic. It is usually created by a secondary dominant that resolves to the target. In C major, D7 leads to G, so G is tonicised for a moment, and the ear hears it as a local home. Unlike modulation, tonicisation does not establish a new key. The music returns to C major, and the home key governs the larger phrase. The test is duration: a tonicisation is too brief to become a new home. Short tonicisations can also be made by a diminished seventh chord, which resolves to the target as if it were a leading-tone chord. Tonicisation is common in Classical and Romantic music.
Related terms
- ModulationA change of tonal centre in which the music settles into a new key with its own tonic and cadence, often through a pivot chord.
- 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.
- 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.
- Diminished seventh chordA four-note chord of stacked minor thirds, such as B D F A♭, which divides the octave into four equal parts and can resolve to several keys.
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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.