Root on A string
no fifthx-11-10-12-11-x
A♭maj9 is the A♭ major 9 chord. Its notes are A♭, C, E♭, G and B♭. It is the same chord as G♯maj9. A major seventh plus a ninth. The compact grip omits the fifth.
x-11-10-12-11-x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every A♭, C, E♭, G and B♭ on the first 12 frets. The filled dots are the root, A♭. Build your own shape from any nearby group.
Other A♭ chords
Other major 9 chords