C7#9b13 Dominant 7th
The C7#9b13 chord is built from the notes C – E – G – Bb – D# – Ab.
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Also known as
C7(#9,b13)C7(#9b13)C7(b13#9)
Chord tones, one by one
CRoot
Root
The fundamental note the chord is built on — C.
EThird
Major third
Four semitones — makes the chord major (brighter, happier).
GFifth
Perfect fifth
Seven semitones — the most stable interval, reinforces the root.
BbSeventh
Minor seventh (♭7)
Ten semitones — the dominant/minor seventh. Adds bluesy tension (7, m7).
D#Extension
Sharp ninth (♯9)
A ♯9 — the gritty 'Hendrix' tension over a dominant chord.
AbExtension
Flat thirteenth (♭13)
A ♭13 — dark altered tension over a dominant chord.
🎼 Related scales
Phrygian ♭4harmonic major scale
🎹 Modal analysis
This chord implies the Phrygian ♭4 scale; its characteristic note is the ♭4 (enharmonic major 3rd). It is a mode of the harmonic major scale.
🎸 Genres
Modern jazz · Post-bop · Fusion

