guitar chord
D♭add9
A major triad with a ninth added and no seventh — which is what tells it apart from a ninth chord.
Written the other way round it is C♯add9 — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
x4314x
hard
9868xx
hard
xxba9b
hard
x4364x
hard · no 5
98b8xx
hard · no 5
What is true of it
D♭add9 is D♭, F, A♭ and E♭ — 1, 3, 5 and 9 counted from D♭.
On an instrument that cannot reach all 4, the 5 goes first, in that order.
The easiest of the 5 fingerings below is x4314x: 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.
2 strings stay silent.
Where its notes are on the neck
The brass dots are D♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
D♭add9/F
141121
D♭add9/A♭
4636xx
D♭add9/E♭
x6666x
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.