Irish bouzouki Aadd9 chord (GDAE)A added ninth: 4 2 4 5, and 3 more shapes

Frets, low course to high: 4 2 4 5 (from the 2nd fret) · Aadd9/B

1. G course: 4th fret, middle finger, B
2. D course: 2nd fret, index finger, E
3. A course: 4th fret, ring finger, C♯
4. E course: 5th fret, little finger, A

Sounds: B E C♯ A  ·  Aadd9 is A, C♯, E, B (1 · 3 · 5 · 9)

Open courses that ring: A and E are notes of Aadd9, so they can drone under it.

With a capo: on the 2nd fret it’s 4 0 0 3 (frets counted from the capo), an open Gadd9 shape.

Tuning GDAE: G D A E, low to high. The octave mandolin uses the same tuning, so these shapes fit it too.