Difference Between add9 and 9 Chords

Difficulty: intermediate

Let's take a look at 3 chord shapes that should be interesting to study together.

Aadd9

5395RE5C#3B9E5AR

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"