A#7b9#5

Q: What notes are in the A#7b9#5 chord?

The A#7b9#5 chord (A# 7b9#5) contains: A#, D, F#, G#, B. Its interval structure is shown above in the Theory section.

Q: How do I build A#7b9#5 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is A#7b9#5 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for A#7b9#5?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

A# 7b9#5

Octaves

Musical context

ChordA#augTriad

ChordA#7b9#5A# 7b9#5

ArpeggioA# majorBroken triad

ScaleA# major7 notes

KeyA# majorMajor key

ProgressionPop axisSequence

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

Theory

General info

Full name: A# 7b9#5
Symbol: A#7b9#5
Root: A#
Quality: 7b9#5

Chord notes

1A#root

3Dmajor 3rd

#5F#aug 5th

b7G#minor 7th

b2Bminor 2nd

Functions & resolutions

Stability / tension: Stable — can serve as major tonic
Most common resolutions: D#D# Major FF Major GmG Minor
Unstable degrees: #5F#
6G
resolves up to the 6th
4D#
b7G#
resolves down to the resolution tonic
Main resolution: A#7b9#5source
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#7b9#5source
Deceptive resolution
GmG Minor
As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).
A#7b9#5source
Modal resolution
G#G# Major
In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.
A#7b9#5source
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#7b9#5source
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: E7E Dominant 7

Features

Character: Dominant, with b9 and #5
Characteristic interval: Augmented 5th (#5), Minor 9th (b9)
Description: The augmented 5th and minor 9th alter two tones of a dominant seventh chord. Both allow semitone voice leading into the next chord, giving the sonority sharp, directed tension.
Application: Jazz cadences V → i
Altered dominant
Harmonic minor

Voicing & structure

Root position

v1A#(A#4)Bass

root

v2D(D5)M3from A#

v3F#(F#5)M3from D

v4G#(G#5)M2from F#

v5B(B5)m3from G#

Harmony

Compatible scales

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

ScaleD Lydian augmented ScaleF# Mixolydian ♭6 ScaleF# Harmonic major ScaleG# Romanian minor ScaleG# Ukrainian Dorian ScaleA# Enigmatic scale ScaleA# Phrygian dominant ScaleA# Altered (super Locrian)ScaleB Melodic minor ScaleB Neapolitan major

This chord on guitar 🎸

See how A#7b9#5 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: GmG minor
Dominant: FF major
Subdominant: EbEb major
Key signature: 2 flats (Bb, Eb)

What to learn next

ScaleBb Chromatic scaleScale to improvise over this chord PracticeChord trainerLock the fingering into muscle memory ProgressionChord progressionsHow this chord works inside real progressions

Recommended for you

Bb Chromatic scaleA scale related to this chord

Bb Enigmatic scaleA scale related to this chord

Bb Altered (super Locrian)A scale related to this chord

Practice

Keyboard Trainer

Reinforce it in practice — play and name notes on the interactive keyboard.

Open Trainer

Test yourself

(Press any key to start)

What notes are in the A#7b9#5 chord?

How do I build A#7b9#5 on the keyboard?

Which keys is A#7b9#5 found in?

What can I substitute for A#7b9#5?