Differences Between Maj9, add9 and 9 Chords

How Are Built Add9, maj9 and 9 Chords?

There can be a bit of confusion for beginner guitarists (and any musicians), so it’s time to clear it all up effectively. First, keep in mind that these three types of chords are built based of a major triad containing : root (R), major third (3) and perfect fifth (5). If you don’t what have a lot of experience or a deep knowledge of triads, please go check this Triad Chord Dictionary.

Here below the C major triad built with C (tonic/root), E (major third) and G (perfect fifth).

Differences Between Maj9 — C-major-triad

(Please note that the term “Tonic” or “Key note” is employed for naming the first note of a scale whereas “Root” is employed for naming the first note of a chord. They both have the same role, which is to define the key.)

To built an add9 chord, you have to add the ninth on the top of the major triad. Thus giving a four note chord : R (root), 3 (major third), 5 (fifth) and 9 (ninth). This should not be confused with sus2 chords (the ninth being the same note as the second). Indeed, suspended second chords don’t have a third but a second instead (R-2-5).
Major 9 chords (maj9) are built from the same major triad but with a major seventh. This is actually a major seventh chord (R-3-5-7) with and ninth.

Dominant 9 chords (9) are also built from the same major triad but they contain a minor seventh (b7). Making them dominant seventh chords (R-3-5-b7) with an extended note (the ninth). Once again they should not be confused with 7sus2 (R-2-5-b7).
The following examples are in the key of C, obviously these rules applies to any key.

Here are three basic shapes showing the differences between add9, maj9 and 9 chords on guitar. These are movable forms, meaning that you can play it anywhere on the neck, the root note giving the name of the chord.

Basic Dominant 9 Chord Shapes (movable)

Here are three ways of playing dominant 9 chords on guitar. The first one have the root note on the 6th string and the second have the root on the fourth string. The third position on the right have a circled root note which is technically hard to play when the ninth is on the first string.

Basic Major 9 Chord Shapes (movable)

These three major 9 guitar chord shapes are derived from the dominant 9 voicings previously seen. You can see and hear the unique difference between these two chords, the seventh which is major in a major 9 chord and minor in a dominant 9 chord.