A#7b5

A# 7b5

Octaves

Musical context

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

Theory

General info

Full name
A# 7b5
Symbol
A#7b5
Root
A#
Quality
7b5

Chord notes

1A#root
3Dmajor 3rd
b5Edim 5th
b7G#minor 7th

Functions & resolutions

Stability / tension
High tension — requires resolution
Most common resolutions
Unstable degrees
3D
4D#
resolves up to the resolution tonic
4D#
b5E
resolves inward to the resolution tonic
6G
b7G#
resolves down to the tonic 3rd
Main resolution
A#7b5source
D#D# Major
Dominant 7th A#7 naturally resolves up a 4th to D#. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions
A#7b5source
Deceptive resolution
CmC Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
A#7b5source
Modal resolution
G#G# Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
A#7b5source
Jazz reharmonization
E7E Dominant 7
Tritone substitution: A#7 can be replaced by E7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
A#7b5source
Functional resolution
A#sus4A# Sus4
The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Substitutions

Tritone substitution

Features

Character
Dominant, with a diminished 5th
Characteristic interval
Diminished 5th (b5), Minor 7th (b7)
Description
The diminished fifth replaces the perfect fifth, adding a tritone to the dominant tension. Sharper than a regular dom7.
Application
  • Tritone substitution
  • Jazz ii-V-I
  • Altered blues

Voicing & structure

Root position

v1A#(A#4)Bass
root
v2D(D5)M3from A#
v3E(E5)M2from D
v4G#(G#5)M3from E

Harmony

Compatible scales

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

This chord on guitar 🎸

See how A#7b5 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