A#m7b5

General info

Full name

A# Half-dim 7

Symbol

A#m7b5

Root

A#

Quality

Half-dim 7

Chord notes

Functions & resolutions

Typical function in key

vii°Leading tone (vii°)B major

Stability / tension

High tension — pulls toward the dominant

Most common resolutions

D#7D# Dominant 7G#mG# Minor

Unstable degrees

2C

b3C#

resolves down to the 2nd

4D#

b5E

resolves inward to the 4th

4D#

b7G#

resolves down to the resolution tonic

Main resolution

A#m7b5source

D#7D# Dominant 7

Half-diminished A#m7b5 typically acts as ii in minor, resolving to the dominant (D#7), which then leads to the tonic.

Other resolutions

A#m7b5source

Deceptive resolution

G#mG# Minor

The half-diminished chord can bypass the dominant and resolve directly to the minor tonic — a plagal turn in minor.

A#m7b5source

No resolution needed

In the Locrian mode, a half-diminished chord can function as the tonic, requiring no resolution.

A#m7b5source

Jazz reharmonization

C#m6C# Minor 6

In jazz, ø7 is common in ii-V-i progressions but can be substituted with iv6, sharing the same notes.

A#m7b5source

Functional resolution

F#F# Major

Besides moving to the dominant, the half-diminished chord can resolve to bVI — creating a Phrygian color.

Features

Character

Half-diminished, unstable

Characteristic interval

Diminished 5th (b5)

Description

The diminished fifth creates instability, the minor seventh softens it. Less tense than fully diminished.

Application

• iiø7 in natural minor
• Jazz ii–V in minor
• Unstable predominant sonorities

Voicing & structure

Harmony

Harmonic context

viim7b5B majorDominantvim7b5C# DorianToniciiim7b5F# MixolydianTonic

Compatible scales

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