C#13b9

C# 13b9

Octaves

Musical context

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name
C# 13b9
Symbol
C#13b9
Root
C#
Quality
13b9

Chord notes

1C#root
3E#major 3rd
5G#perfect 5th
b7Bminor 7th
b2Dminor 2nd
6A#major 6th

Functions & resolutions

Stability / tension
Stable — can serve as major tonic
Most common resolutions
Unstable degrees
4F#
b7B
resolves down to the resolution tonic
Main resolution
C#13b9source
G#G# Major
Major chord C# is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.
Other resolutions
C#13b9source
Deceptive resolution
A#mA# Minor
As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).
C#13b9source
Modal resolution
BB Major
In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.
C#13b9source
Jazz reharmonization
C#maj7C# Major 7
In jazz, a major chord is enriched to maj7, 6/9, or add9 and can smoothly transition into a ii-V of another key (modulation).
C#13b9source
Functional resolution
G#G# Major
As the IV degree (subdominant), a major chord can resolve to V or directly to I (plagal cadence).

Substitutions

Tritone substitution

Features

Character
Dominant, with b9 and 13th
Characteristic interval
Minor 9th (b9), 13th
Description
The minor 9th sharpens dominant tension, while the major 13th adds a consonant extension. The contrast between b9 and 13 makes the chord dense while preserving a clear dominant function.
Application
  • V13b9 → i in minor
  • Latin jazz
  • Advanced jazz cadences

Voicing & structure

Root position

v1C#(C#4)Bass
root
v2E#(E#4)M3from C#
v3G#(G#4)m3from E#
v4B(B4)m3from G#
v5D(D5)m3from B
v6A#(A#5)m6from D

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.

This chord on guitar 🎸

See how C#13b9 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

CAmGEmDBmAF#mEC#mBG#mF#D#mDbBbmAbFmEbCmBbGmFDmDbmajor
Relative key
Dominant
Subdominant
Key signature
5 flats (Bb, Eb, Ab, Db, Gb)

Practice

Keyboard Trainer

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Frequently Asked Questions