A♭dim

A♭1C♭♭3E♭♭♭5

Two minor thirds stacked. The fifth is diminished, so it cannot be dropped without losing the chord.

Written the other way round it is G♯dim — the same twelve keys on a piano, a different piece of notation.

on guitar on piano the scale

Every fingering that fits a hand

Fig. 2

1242

moderate

Fig. 3

x875

easy

What is true of it

A♭dim is A♭, C♭ and E♭♭ — 1, b3 and b5 counted from A♭.

E♭♭ is a double flat, and it has to be: every letter from A♭ upwards is used once, so the b5 cannot be written any other way.

The easiest of the 2 fingerings below is 1242: 4 fingers, held at the 1st fret.

None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.

Where its notes are on the neck

Fig. 4 — first 12 frets

The brass dots are A♭, the root. Everything else is a chord tone with its degree printed in it.

With a different note underneath

first inversion

A♭dim/C♭

4242

second inversion

A♭dim/E♭♭

x242

An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.

A♭ in other shapes

A♭major A♭mminor A♭augaugmented A♭5power chord A♭sus2suspended second A♭sus4suspended fourth

Cdim C♯dim D♭dim Ddim D♯dim E♭dim Edim Fdim all 374