It sounds sharp-edged. The ninth grinding a whole step under the minor third is the edge an m9 softens.
4 moveable shapes. None has an open string in it, so each one plays every root there is; the dots are degrees, and R is the root.
Pick a root and every diagram below moves to it. Nothing about any of the grips changes — only the fret they start on, and each one starts somewhere different because they are rooted on different strings.
Showing Cmadd9. Every voicing of it, open strings included, is on its own chord page.
The lowest root available, so these are the fullest-sounding shapes and the ones that carry a band. F at the first fret, G at the third, A at the fifth: the shape is the same and the fret is the whole of the difference.
8-10-10-8-8-10
6 notes · 3 frets
The other half of the pair. Almost every progression is played by alternating these with the low E shapes, because a root a fourth up the neck is a root two frets along the string below — the hand barely moves.
x-15-13-12-15-x
4 notes · 4 frets
The same chord with something other than the root underneath. You reach for one of these because of what the bass is doing, not because of what the chord is — a bass line that walks while the harmony stays put is made of these.
♭3 in the bass. 2 ways to get it.
♭3 on the A string, root on the G string
x6553x
4 notes · 4 frets
♭3 on the D string, root on the B string
x-x-13-12-13-10
4 notes · 4 frets
Every voicing of one particular madd9 chord — including the open-string ones that do not move — is on that chord's own page, linked under each shape above. All the moveable shapes for every quality are on the shapes index, and the minor chords as a family are on their own page.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.