The 9th chord (guitar II)

A ninth chord takes the 7th chord to a new level (literally).

The photo below shows the addition of the 9th to a 7th chord.

If we simply want to add a 9th to a basic triad (3 note chord), we call the chord an "add 9" chord.
The examples below are basic open position chords that have an "add 9"

The term "Major 9th" implies that the chord already has a Major 7th in the chord.
Below you can see an example of a CMajor9 chord. In this case, the "Major" refers to the fact that the chord is both Major and has a Major 7th.

Below you see an example of a Dominant 9 chord. This chord would likely be written as "C9". A dominant 9th implies that the chord already has a dominant 7th in it. In this case dominant means a Major triad with a flatted 7th. The 9th gets added above that. The notes of a C9 chord would be C, E, G, Bb, D