guitar chord
A♭9
A dominant seventh carrying a ninth on top.
Written the other way round it is G♯9 — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
464546
hard · barre
4343xx
hard · no 5
xx6576
hard · no 5
xbabbx
hard · no 5
What is true of it
A♭9 is A♭, C, E♭, G♭ and B♭ — 1, 3, 5, b7 and 9 counted from A♭.
On an instrument that cannot reach all 5, the 5 and 1 go first, in that order.
The easiest of the 4 fingerings below is 464546: 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.
1 of the 4 need a barre.
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♭9/C
898898
A♭9/E♭
xx1312
A♭9/G♭
2313xx
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.