Notes and intervals of A♯ half-diminished
- A♯1 · root
- C♯♭3 · minor third
- E♭5 · diminished fifth
- G♯♭7 · minor seventh
It's the second degree in minor keys (iiø–V7–i), very common in boleros, tango and jazz.
Progressions with A♯m7♭5
ii–V–i in minor: iiø7 – V7 – i
The minor cadence of boleros, tangos and jazz, in G♯ natural minor.
Which keys contain A♯ half-diminished?
A♯m7♭5 belongs to 2 keys: in each one it plays a different role depending on the degree (the Roman numeral).
| Key | Degree |
|---|---|
| B major | viiø7 |
| G♯ natural minor | iiø7 |
Frequently asked questions
What notes are in the A-sharp half-diminished chord?
A♯ half-diminished (A♯m7♭5) has 4 notes: A♯ (root), C♯ (minor third), E (diminished fifth), G♯ (minor seventh).
How do you play A♯ half-diminished on guitar?
The most common shape starts at fret 1: x 1 2 1 2 x (from the 6th to the 1st string). Finger 1 (index finger) on fret 1 of the 5th string (A). Finger 3 (ring finger) on fret 2 of the 4th string (D). Finger 2 (middle finger) on fret 1 of the 3rd string (G). Finger 4 (pinky) on fret 2 of the 2nd string (B). Do not play the 6th or 1st strings: strum from the 5th string.
Is A♯m7♭5 the same as B♭m7♭5?
Yes: A♯ half-diminished and B♭ half-diminished sound and are played the same (they are enharmonic). The spelling depends on the song's key; you'll see both names in sheet music and songbooks.
How do you write A♯ half-diminished in chord notation?
It's written A♯m7♭5; you'll also see A♯ø or A♯m7b5. Chord symbols use letter names for notes: C, D, E, F, G, A and B.