Learn › A Flat Diminished 7th Chord on Piano (Abdim7)
New Released in April 2026
A Flat Diminished 7th Chord on Piano (Abdim7)
A flat diminished 7th (Abdim7) is spelled Ab - Cb - Ebb - Gbb. It sounds like Abdim with an extra Gbb, the note that gives it its tense, dramatic colour. Learn the shape and the inversions, then practise Abdim7 by playing.
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- MIDI keyboard
- Digital or acoustic piano
- Guitar
- Computer, phone or tablet
Abdim7 inversions on the keyboard
In the 3rd inversion Gbb is the lowest note: the seventh in the bass.
Root position: Ab Cb Ebb Gbb
1st inversion: Cb Ebb Gbb Ab
2nd inversion: Ebb Gbb Ab Cb
3rd inversion: Gbb Ab Cb Ebb
How to play Abdim7 on the piano
| Hand | Ab | Cb | Ebb | Gbb |
|---|---|---|---|---|
| Right hand | 1 (thumb) | 2 | 3 | 5 (little) |
| Left hand | 5 (little) | 3 | 2 | 1 (thumb) |
Too much stretch? Play Ab alone in the left hand and Cb Ebb Gbb in the right.
A three-note Abdim7
Root, third, seventh: Ab Cb Gbb. It is the shape to learn first, and it moves smoothly to the next chord.
Four 7th chords on Ab
Same root, same fifth: watch the third and the seventh.
Abdim7 in keys and progressions
- Abdim7 is the vii°7 chord of A minor: it pulls up one key, Abdim7 → A / Am.
- Every note is three keys above the one before, so Abdim7, Bdim7, Ddim7 and Fdim7 use the same four keys.
- That even spacing is why Abdim7 sounds tense, dramatic and can lead to several different chords.
- Cb is the same key as B.
- Ebb is the same key as D.
- Gbb is the same key as F.
vii°7 → i: Abdim7 → Am
A 5-minute Abdim7 routine
- Start in root position: Ab, Cb, Ebb, Gbb, four times, eyes on the symbol.
- Walk up through the inversions (Cb Ebb Gbb Ab, Ebb Gbb Ab Cb, Gbb Ab Cb Ebb) without lifting the whole hand.
- Play it in its ii-V-I, Abdim7 → Am, four beats per chord.
- Finally meet it in random order between other chords, with a check on every note.
Short daily rounds fix Abdim7 in memory faster than one long practice a week.
Make Abdim7 automatic
In ChordRunner Abdim7 and every other chord ride towards your runner: play them in time. MIDI keyboard or microphone, both work.
Play the demoCommon questions
What is the difference between Abdim7 and Abdim?
Abdim7 adds one note to the Abdim triad: Gbb, the diminished seventh. That fourth note is what makes it a seventh chord.
Can I play Abdim7 with three notes?
Yes. Leave out the fifth and play Ab Cb Gbb: root, third and seventh. It still sounds like Abdim7 and is easier for the left hand.
Where does Abdim7 go?
Abdim7 is the vii°7 chord of A minor: it pulls up one key, Abdim7 → A / Am. Every note is three keys above the one before, so Abdim7, Bdim7, Ddim7 and Fdim7 use the same four keys.
Can I practise Abdim7 with a MIDI keyboard?
Yes. In ChordRunner a USB MIDI keyboard is detected automatically, and an acoustic piano works through the microphone. Abdim7 counts in any inversion, as long as Ab, Cb, Ebb, Gbb sound together.
Your instrument is the controller.
ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.
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