Aadd9

This interesting Aadd9 shape combines a 3rd (C#) in close proximity to a 9th (B).  The presence of the C# makes this chord an "add9" instead of a "2"

Amaj9

This Amaj9 shape omits the 3rd (C#), which makes it a bit ambiguous, but the presence of the 7th (G#) and 9th (B) make the best description for this chord Amaj9.

This A9 shape omits the 3rd (C#), which makes it a bit ambiguous, but the presence of the b7th (G) and 9th (B) make the best description for this chord A9.

Difference Between add9 and 9 Chords

Diagram Collection

Aadd9