A Flat Diminished (also written G#dim)
Abdim is made of 3 notes: Ab, Cb (B) and Ebb (D). Here it is in root position, with Ab at the bottom.
Inside Notley Piano: all the inversions of Abdim, 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 |
A diminished chord stacks two minor 3rds, so it has a flat 5th. It sounds tense and unstable, and is usually used as a passing chord.