What notes are in an A♯ half-diminished chord?

A♯ half-diminished contains four notes: A♯ (root), C♯ (minor third), E (diminished fifth), and G♯ (minor seventh).

Is A♯m7♭5 the same as B♭m7♭5?

Enharmonically yes — same four pitches in different spellings. A♯m7♭5 lives inside G♯-minor key contexts; B♭m7♭5 (B♭-D♭-F♭-A♭) is rarer in practice because of the F♭.

How does A♯m7♭5 resolve?

In G♯ minor: A♯m7♭5 → D♯7 → G♯m. The chord prepares the dominant D♯7, which resolves to the G♯m tonic.

Where does A♯ half-diminished appear in music?

In G♯-minor cadences in classical literature — Beethoven's late piano sonatas, Liszt's sharp-key piano works, and any other deep sharp-side music in G♯ minor.

A# half-diminished chord — notes, intervals, and practice

A♯ half-diminished (A♯m7♭5 or A♯ø) — A♯, C♯, E, G♯ — is the iiø7 of G♯ minor. The chord serves the minor-key cadence in G♯-minor literature, which though rarer than C♯ or A♯ minor as tonics, does appear in Beethoven (Op. 106 development) and Liszt.

Intervals

The A# half-diminished chord stacks two thirds on the root. Each interval and its size in semitones:

A#→C#minor 3rd3 semitones
C#→Eminor 3rd3 semitones
E→G#major 3rd4 semitones

On the keyboard

Each note of the A# half-diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the A# half-diminished chord on a six-string guitar fretboard.

Common mistakes

A♯m7♭5 has three sharps (A♯, C♯, G♯) plus one natural (E). The natural fifth (E, lowered from E♯ in A♯ minor) is the chord's flat-five — the half-diminished identity. The chord is enharmonically the same set of pitches as B♭m7♭5 (B♭-D♭-F♭-A♭), but the sharp-side spelling preserves consistency in G♯-minor key contexts.

In context

A♯m7♭5 → D♯7 → G♯m is the ii–V–i in G♯ minor. Beethoven's "Hammerklavier" Sonata Op. 106 uses dense chromatic minor-key harmony where A♯m7♭5 appears as part of the development's tonal explorations.

Drill it

The A# half-diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in an A♯ half-diminished chord?: A♯ half-diminished contains four notes: A♯ (root), C♯ (minor third), E (diminished fifth), and G♯ (minor seventh).
Is A♯m7♭5 the same as B♭m7♭5?: Enharmonically yes — same four pitches in different spellings. A♯m7♭5 lives inside G♯-minor key contexts; B♭m7♭5 (B♭-D♭-F♭-A♭) is rarer in practice because of the F♭.
How does A♯m7♭5 resolve?: In G♯ minor: A♯m7♭5 → D♯7 → G♯m. The chord prepares the dominant D♯7, which resolves to the G♯m tonic.
Where does A♯ half-diminished appear in music?: In G♯-minor cadences in classical literature — Beethoven's late piano sonatas, Liszt's sharp-key piano works, and any other deep sharp-side music in G♯ minor.