08/04/2026
ALL ABOUT ALTERED CHORDS ON THE PIANO
1️⃣ What Is an Altered Chord?
An altered chord is typically a **dominant 7th chord (V7)** where one or more of these notes are raised or lowered:
* ♭9
* ♯9
* ♭5 (♯11)
* ♯5 (♭13)
So instead of:
C7 = C–E–G–B♭
You get:
* C7♭9
* C7♯9
* C7♭5
* C7♯5
* C7♭9♯5
* C7♯9♭5
* etc.
When you see *C7alt*, it means:
> Play a dominant 7 chord with one or more altered tensions (♭9, ♯9, ♭5, ♯5).
2️⃣ Why Altered Chords Work
Altered chords increase tension before resolution.
Example in C minor:
G7 → Cm
Now add alteration:
G7♭9 → Cm
G7♯9♭13 → Cm
The altered notes create extra dissonance that resolves beautifully into the tonic.
This sound is everywhere in:
* Jazz standards
* Gospel progressions
* Bebop
* Fusion
* Film scoring
Used heavily by pianists like:
* Bill Evans
* Herbie Hancock
* McCoy Tyner
3️⃣ The Four Main Alterations
On a dominant 7 chord:
🔹 ♭9
Lower the 9 by a half step.
C7♭9
C–E–G–B♭–D♭
Very dark, classical tension.
🔹 ♯9
Raise the 9 by a half step.
C7♯9
C–E–G–B♭–D♯
Classic “Hendrix chord” sound.
Used famously by:
* Jimi Hendrix
🔹 ♭5 (♯11)
Lower the 5.
C7♭5
C–E–G♭–B♭
Creates tritone expansion.
🔹 ♯5 (♭13)
Raise the 5.
C7♯5
C–E–G♯–B♭
Very dramatic, pulls strongly to minor chords.
4️⃣ The Fully Altered Chord (7alt)
When you see:
C7alt
It implies:
* Root
* 3rd
* 7th
* Some combination of ♭9, ♯9, ♭5, ♯5
Often played WITHOUT the natural 5.
Example voicing:
Left hand: C
Right hand: E – B♭ – D♭ – A♭
That’s C7♭9♭13.
5️⃣ The Altered Scale (Super Locrian)
The scale used over altered chords is:
**The 7th mode of melodic minor**
For C7alt → use D♭ melodic minor.
Scale degrees:
C – D♭ – E♭ – E – G♭ – A♭ – B♭
Formula:
1 ♭9 ♯9 3 ♭5 ♯5 ♭7
This scale contains ALL possible alterations.
