A♯dim7 chord on piano
A♯dim7 is A♯, C♯, E and G. A♯ sits on the last black key of the group of three. Play it once at full speed, then at a quarter to hear every note.
root position · A♯–C♯–E–G · right hand 1-2-3-5
- Notes
- A♯ · C♯ · E · G
- Formula
- 1 · ♭3 · ♭5 · ♭♭7
How to play A♯dim7 on piano
Count keys (black and white) from A♯: 3 half steps up to C♯, 3 half steps up to E then 3 half steps up to G. That's the whole chord: 4 keys.
- Right hand: 1 on A♯, 2 on C♯, 3 on E and 5 on G.
- Left hand: 5 on A♯, 3 on C♯, 2 on E and 1 on G.
- On the keyboard it's black, black, white and white keys, the same pattern as D♯dim7, so your hand shape carries over.
A♯dim7 inversions
- root position: A♯–C♯–E–G. Right hand 1-2-3-5.
- 1st inversion: C♯–E–G–A♯, with C♯ at the bottom. RH 1-2-3-5.
- 2nd inversion: E–G–A♯–C♯ (E in the bass). RH 1-2-3-5.
- 3rd inversion: G–A♯–C♯–E, G lowest. Fingers 1-2-3-5.
Nobody plays every chord in root position. The inversions let A♯dim7 sit wherever the previous chord left your hand.
Moving between A♯dim7 and its neighbours
The chords A♯dim7 usually goes to, and what changes under your fingers.
- B (leads up a half step): A♯dim7 to B: play B in root position (B–D♯–F♯), while A♯ moves up to B, E down to D♯ and G down to F♯. B on piano
- Bm (leads up a half step): A♯dim7 to Bm: play Bm in root position (B–D–F♯), while A♯ moves up to B, C♯ up to D and G down to F♯. Bm on piano
- E♭ (a fifth down): A♯dim7 to E♭: play E♭ in 2nd inversion (B♭–E♭–G) and B♭ and G stay under the same fingers, while E moves down to E♭. E♭ on piano
A♯dim7 is a diminished seventh: three minor thirds stacked, so the chord divides the octave into four equal parts. A♯dim7 can stand in for a dominant seventh a half step below, which is why it links chords so smoothly. Play it solid and then broken to hear the difference.
A short A♯dim7 drill
Play A♯dim7 broken, one key at a time: A♯, C♯, E, G, E, C♯, A♯. Then press the keys together and check that all 4 sound at the same volume. Finish with the inversions in order: A♯–C♯–E–G; C♯–E–G–A♯; E–G–A♯–C♯; G–A♯–C♯–E.
The keys of A♯dim7
A♯dim7 is a diminished seventh chord, 1–♭3–♭5–♭♭7 from A♯. Root position, from the bottom: how A♯dim7 is built.
| Note | Key | Fingers | Role |
|---|---|---|---|
| A♯ | black key | RH 1 · LH 5 | root |
| C♯ | black key | RH 2 · LH 3 | minor third |
| E | white key | RH 3 · LH 2 | diminished fifth |
| G | white key | RH 5 · LH 1 | diminished seventh |
You may also see it as B♭dim7; nothing changes on the piano.
Keys and progressions with A♯dim7
A♯dim7 on guitar and ukulele
Switching instruments? Try A♯dim7 on ukulele or A♯dim7 on guitar, or compare them on the A♯dim7 chord page.
Related A♯ chords on piano
Other diminished seventh chords
A♯dim7 on piano: questions
What notes are in A♯dim7 on piano?
A♯, C♯, E and G: A♯ (black key), C♯ (black key), E (white key) and G (white key). Right hand 1-2-3-5, left hand 5-3-2-1.
How do you play A♯dim7 on piano?
Press A♯, C♯, E and G together (2 black, 2 white). Right hand: 1 on A♯, 2 on C♯, 3 on E and 5 on G.
What are the inversions of A♯dim7?
1st inversion (C♯–E–G–A♯), 2nd inversion (E–G–A♯–C♯) and 3rd inversion (G–A♯–C♯–E), after root position (A♯–C♯–E–G). Same notes, a different one at the bottom.
What does A♯dim7 look like on the keyboard?
black, black, white and white keys, the same pattern as D♯dim7, so one hand shape covers all of them.
Every shape above plays only A♯, C♯, E and G, checked by the site's tests. Updated September 2026.