A Flat Diminished 7th (also written G#dim7)
Abdim7 is made of 4 notes: Ab, Cb (B), Ebb (D) and Gbb (F). Here it is in root position, with Ab at the bottom.
Inside Notley Piano: all the inversions of Abdim7, fingering for both hands, a play button, and practice that helps you remember it.
| Note | Degree | Interval from Ab |
|---|---|---|
| Ab | 1 | root |
| Cb (B) | b3 | minor 3rd |
| Ebb (D) | b5 | diminished 5th |
| Gbb (F) | bb7 | diminished 7th |
A diminished 7th chord stacks three minor 3rds. It sounds dramatic and spooky, and every note is the same distance apart, so the same shape repeats every three frets.