guitar chord
A♭13
Seven notes in theory and four or five in anyone’s hands: root, third, seventh and thirteenth carry it.
Written the other way round it is G♯13 — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
464564
hard · barre · no 9
46456x
hard · barre · no 9
xbdbdd
hard · barre · no 9
What is true of it
A♭13 is A♭, C, E♭, G♭, B♭ and F — 1, 3, 5, b7, 9 and 13 counted from A♭.
On an instrument that cannot reach all 6, the 5, 9 and 1 go first, in that order.
The easiest of the 3 fingerings below is 464564: 4 fingers, one of them barring the 4th fret, held at the 4th 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.
It leaves out the 9. 6 strings cannot carry 6 notes, and the 9 is the one this chord can lose without changing what it is.
Where its notes are on the neck
The brass dots are A♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
A♭13/C
888b98
A♭13/E♭
bbdbdd
A♭13/G♭
2333xx
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.