The altered dominant is one of the most powerful and colourful chords in jazz-influenced harmony — bringing intensity, surprise, and sophistication to progressions, solos, and compositions.
What Is a Dominant Chord?
The dominant 7 chord is built on the 5th degree of the scale: root, major 3rd, perfect 5th, and minor 7th (e.g., G7: G–B–D–F). Dominant 7 chords naturally create tension that resolves to the tonic, driven by the tritone between the 3rd and 7th.
What Are Altered Dominants?
An altered dominant is a dominant 7 chord where the 5th and/or 9th are raised or lowered:
- ♭9 (flat ninth)
- ♯9 (sharp ninth)
- ♭5 (flat fifth / ♯11)
- ♯5 (sharp fifth / ♭13)
In C major, the dominant is G7. Altered versions include G7♭9, G7♯9, G7♭5, G7♯5, or combinations like G7♭9♯5. These alterations introduce chromatic colour and heightened dissonance, intensifying the pull toward resolution.
Why Altered Dominants Work
They exaggerate the voice-leading tendencies already present in a normal dominant 7 chord. Altered 9ths resolve naturally by step into chord tones of the tonic. Altered 5ths create extra half-step motion. The tritone remains intact, so the chord still unmistakably functions as a dominant — just with more drama.
The Altered Scale
The altered scale (super-Locrian) is the 7th mode of the melodic minor scale. For G altered: take A♭ melodic minor and start from G — G–A♭–B♭–B–D♭–E♭–F. All altered tensions are present in one place.
Using Altered Dominants
In a ii–V–I: Dm7 – G7alt – Cmaj7. G7alt maximises the tension before resolving beautifully into Cmaj7. Common voicings include the 7♯9 chord (Hendrix's "Purple Haze" chord: E7♯9). Practice the altered scale over V7alt chords to get comfortable with the sound.