Secondary dominants are dominant chords that temporarily tonicize a chord other than the home key, treating it as if it were a new "tonic." They add color and forward motion to chord progressions by creating brief moments of tension and resolution outside the primary key center.
- Temporary dominant function for non-tonic chords.
- Create brief tonal shifts and increased harmonic interest.
- Notated as V7/x, where x is the chord being tonicized.
A secondary dominant temporarily tonicizes a chord other than the tonic, providing momentary emphasis and forward motion to that chord.
Using secondary dominants adds harmonic interest, creates brief tension and resolution, and temporarily tonicizes a chord.
A secondary dominant is written as V7/x, indicating a dominant 7th chord targeting the 'x' chord as a temporary tonic.
Function and Notation
Secondary dominants function as dominant chords (V or V7) for chords other than the tonic. If the target chord is "x", its secondary dominant is labeled V7/x.
- They precede the chord they tonicize (x), applying dominant function to it.
- The target chord (x) can be major or minor, but it's usually treated as if it’s a temporarily important tonic.
- Example: In C major, if you want to tonicize D minor (ii), you use A7 (V7/ii) before Dm.
For the iii chord in C major, the secondary dominant is labeled V/iii, and the dominant chord is E7.
The secondary dominant targeting the IV chord is notated as V7/IV.
Introducing a secondary dominant creates forward motion and highlights the approached chord.
Major Key Examples
| Target Chord (x) | Secondary Dominant (V7/x) | Notes for V7/x | Example in C Major |
|---|---|---|---|
| I | V7 | G-B-D-F | C: G7 → C |
| IV | V7/IV | D-F#-A-C | C: D7 → F |
| V | V7/V | A-C#-E-G | C: A7 → G |
| ii | V7/ii | A-C#-E-G | C: A7 → Dm |
| iii | V7/iii | E-G#-B-D | C: E7 → Em |
- V7/x chord contains the dominant 7th built on the root that leads to x.
- Secondary dominants introduce accidentals (e.g., C# or F# in C major), signaling the brief shift.
Common target chords for secondary dominants in a major key include ii, iii, IV, and V.
In G major, the secondary dominant for the IV chord is V7/IV, so C7 leads to F major.
Secondary dominants often introduce sharps that are not in the home key, like C# or F# in C major.
Minor Key and Modal Usage
In minor keys, secondary dominants work similarly but often appear as major or dominant 7th chords, which introduces even more chromaticism due to the minor scale’s different structure.
- Example: In A minor, the secondary dominant for iv (Dm) is A7 (V7/iv).
- They can also be used to tonicize modal interchange chords or borrowed chords.
In minor keys, secondary dominants are major or dominant7 chords that introduce chromaticism.
In A minor, the secondary dominant for iv is A7, which tonicizes Dm and adds tension.
Guitar Application
On guitar, secondary dominants are played as dominant 7th chords on the fretboard, often leading to their target chord. Knowing the theory helps you predict and use chromatic passing chords for smoother progressions.
- Recognize targets: If the next chord is IV, try V7/IV before it.
- Use common dominant7 shapes and move them to the right root for V7/x.
Recognizing secondary dominants helps anticipate and smooth transitions, improving musicality.
Useful strategies include learning dominant7 shapes, applying them to various roots, and predicting target chords.
Conclusion
Secondary dominants are powerful tools for enriching harmonic progressions by temporarily spotlighting chords through dominant tension.
- They create forward momentum and fresh tonal colors in progressions.
- Understanding their function and notation empowers deeper musical insight and creativity.