A#13b9

A# 13b9

Octaves

Musical context

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

Theory

General info

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

Chord notes

1A#root
3Dmajor 3rd
5E#perfect 5th
b7G#minor 7th
b2Bminor 2nd
6Gmajor 6th

Functions & resolutions

Stability / tension
Stable — can serve as major tonic
Most common resolutions
Unstable degrees
4D#
b7G#
resolves down to the resolution tonic
Main resolution
A#13b9source
FF Major
Major chord A# is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.
Other resolutions
A#13b9source
Deceptive resolution
GmG Minor
As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).
A#13b9source
Modal resolution
G#G# Major
In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.
A#13b9source
Jazz reharmonization
A#maj7A# 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).
A#13b9source
Functional resolution
FF 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

v1A#(A#4)Bass
root
v2D(D5)M3from A#
v3E#(E#5)m3from D
v4G#(G#5)m3from E#
v5B(B5)m3from G#
v6G(G6)m6from B

Harmony

Compatible scales

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

This chord on guitar 🎸

See how A#13b9 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

CAmGEmDBmAF#mEC#mBG#mF#D#mDbBbmAbFmEbCmBbGmFDmBbmajor
Relative key
Dominant
Subdominant
Key signature
2 flats (Bb, Eb)

Practice

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Frequently Asked Questions