Secondary dominant
A secondary dominant is a dominant chord that resolves a fifth downwards into a chord that is not the tonic. It briefly borrows the tension of a neighbouring key, without the piece modulating there. The best known is V/V, the dominant of the dominant.
- Structure
- dominant chord, mostly as a seventh chord
- Resolution
- a fifth downwards, into a chord other than the tonic
- Notation
- V/V, read “five of five”
- Example in C major
- D7 resolves to G
- Not to be confused with
- modulation
The dominant of something that is not the tonic
The page Circle of fifths sets out the basic idea: the circle is also a pattern of chord movement. The strongest movement in tonal music is a fifth downwards: G to C, D to G, A to D. Almost every cadence in Western music uses this pull.
A secondary dominant is, according to the page, a dominant chord that resolves a fifth downwards into a chord that is not the tonic. The notation V/V, read “five of five”, means the dominant of the dominant. In C major V is G, so V/V is D7, a chord that does not belong to C major by nature but resolves wonderfully to G.
D7 as V/V in C major
The chord D–F♯–A–C is a dominant seventh chord on D. The F♯ does not belong to C major and is the leading tone to G. The note that leads out of the key is marked.
Through secondary dominants composers borrow, according to the page, brief tension from neighbouring keys without committing to a full modulation. The difference: in a modulation the piece stays in the new key, the secondary dominant only brushes it in passing.
| Key | Dominant (V) | Secondary dominant (V/V) |
|---|---|---|
| C major | G | D7 |
| G major | D | A7 |
| F major | C | G7 |
| D major | A | E7 |
Why it works
The dominant seventh chord contains two notes that push in opposite directions. The article The leading tone shows it with G7: the B wants to go a semitone up to C, the F a semitone down to E. The same holds for every dominant seventh chord, so also for D7 in C major: the F♯ pulls to G, the C to B. Because the chord contains a note that does not belong to the home key, it sounds like a brief visit to the neighbouring key.
The page One pattern predicts the chords of almost any pop song names where the simple four-chord pattern stops: as soon as secondary dominants, minor subdominants or modulations come into play, it no longer works, and it is at exactly these places that music becomes interesting.
In the chorale
The page German Song Sheets names Crüger's “Nun danket alle Gott” as an example: in the chorales a four-part setting with passing notes, suspensions and occasionally a secondary dominant lies under the melody. On the song sheet the place can be read off from the chord symbols:
Songs
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Nun danket alle Gott Johann Crüger, chorale · voice with chords · 1 page
The song is in G major, 4/4. In the third line the sequence G – D – A7 – D is written above the melody. The A7 resolves to D, in G major therefore the dominant of the dominant.
The sequence A7–D in the chorale is the same V/V–V motion as in the second listening example above.
Common mistakes
- Taking every raised note for a modulation: A note outside the key can be a secondary dominant, the key stays the same.
- Not resolving the chord: The secondary dominant demands that the target chord follows a fifth lower.
- Confusing V/V with V: V is the dominant of the key, V/V the dominant of the dominant, in C major D7 instead of G.
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Related terms
DominantDominant seventh chordModulationCircle of fifthsCadenceDiatonic chordTonic
Editor: Maik Krohm · reviewed on 3 October 2026
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