A secondary dominant is an altered chord having a dominant or leading tone relationship to a chord in the key other than the tonic. An altered chord is a chord containing at least one tone that is foreign to the key. Using secondary dominants results in the tonicization of the chord of resolution.
How are secondary dominants formed?
Writing Secondary Dominants
- Find the the root of the chord after the secondary dominant (the Roman numeral under the slash). It is a major or minor triad.
- Find the pitch a P5 above the root. ...
- Build a dominant seventh chord or major triad on this pitch. ...
- Resolve the chordal 7th (down) and the secondary leading-tone (up).
How do you read secondary dominants?
In a nutshell, a secondary dominant chord is borrowed from another key. So when you see a secondary dominant chord you have to ask yourself, “This secondary dominant is the 'V7' of what chord?” Looking at the chord progression above ask yourself, “D7 is the 'V7' of what chord?” The answer is that D7 is the 'V7' of G.
