3 Different Types of 9th Chords
By Dennis Winge
Ninth chords spice up basic triad chords big-time. If you want to: a) give your chords more depth & character; b) enhance your knowledge & use of music theory by beginning the process of understanding how chord extension works; or c) improve your fretboard knowledge by being able to find extensions like the 9th, then learning 9th chords will be well worth your while.
There are 3 classifications of chords to which we will add 9ths: major, dominant, and minor. Let’s look at each in turn.
I. Major Family
A major triad chord is the intervals 1, 3, and 5 of whatever the root of the chord is. This means that if you’re in the key of B, 1, 3 and 5 are b, d# and f#, since those notes are the first, third, and fifth scale degrees of a B major scale. Because notes 1 and 8 are octaves of each other (both are the note b), then the 2 and the 9 must also be the same. (The same is true for the 4th and the 11th as well as the 6th and the 13th).
When you add a 9th to 1, 3 and 5, the chord becomes an “add 9.” When the 3rd becomes a 2, the resulting 1, 2, 5 becomes a “sus 2” chord. Because these 2 chords are both in the major chord family, they can substitute for each other. So even though in theory they are different, we are going to use both sus2 and add9 chords interchangeably for this article.
[Side note: there is also the “major 9” chord which means that you’d be adding a 9th to 1, 3, 5, and 7. The resulting chord, in the key of D for example, consists of the notes d, f#, a, c# and e. The chord name is Dmaj9, and could also be written A/D because the a, c#, and e make an A triad, but that is a subject for another article, and we will not go further into major 9th chords here.]
The chord progression we’ll use is || Gadd9 | Bbadd9 | Cadd9 | F add9 Ebadd9 ||
Here are some ways to play it:
Notice that for each 4-bar cycle, I chose voicings that were in the same position. This is simply to get you to think about how the various 9th chord shapes overlap, rather than just taking one voicing and moving it up and down the neck.
II. Dominant Family
A “dominant” chord means a 7th chord, which is 1 3 5 b7 (unlike the major 7 mentioned earlier, which is 1 3 5 7). When you add a 9th to a 7th chord (i.e. 1 3 5 b7 9), the resulting chord is just called a 9th chord. Some common ways to play this are:
Notice that the 2nd and 4th voicings above do not have a c note in them at all. If we weren’t in the context of the root of c, the notes e, g, bb, d would be called an Em7b5. Because the 1, b3, b5 and b7 of an Em7b5 are the same as the 3, 5, b7, and 9 of a C9 chord, we can use the Em7b5 as a substitute for C9. This works especially well in a band setting where the bassist is playing the c root and the guitarist/pianist plays the rest of the chord.
A simple progression of | C9 | F9 | G9 | F9 | might be played like this:
III. Minor 9
The minor 9 is 1 b3 5 b7 9. Using F#m9 as our example, the most common voicings are:
Here are some things to notice about the above voicings:
1. The first chord looks like the second bar of the | C9 | F9 | G9 | F9 | progression we saw in part II. Here the F9 chord is moved up 2 frets for the key of G and the major third of the F9 is dropped to a minor 3rd, making it Gm9.
2. The second chord is the same voicing as the 7th bar in part II (the G9 chord), also with its 3rd dropped to a flat 3rd.
3. The third voicing is the same as the chord in bar 3 of the progression in part II, also with its 3rd flattened. The resulting chord of this third voicing, taken out of the context of the g root, is a Bbmaj7. In the same way that the Em7b5 substituted for G9, the Bbmaj7 can substitute for Gm9. The key of Bb is the relative major of G minor, so you can always substitute a maj7 chord whose root is the relative major of the min9 chord you are substituting for.
Well, I know that’s a mouthful. This gives you a lot to work on. As to how and when to use these, that requires a bit more theory, but in short I will say, you must use your ear and make sure that the 9th chord really fits and doesn’t clash with the melody. If the melody is a flat 9 or sharp 9 against a 7th chord, then the 9th chord is a poor choice because the 9 will clash with the b9 or #9. For now though, just get to know these 9th chords and get the help of a teacher as to how to implement them.
About the author: Dennis Winge is a pro guitarist, composer and teacher who has released 6 instrumental albums to date. His guitar school serves Guitar Instruction Ithaca and the surrounding areas.