BLUES
Chord Extensions
By JoHn GAnAPES And dAvId RooS
From Jazzin’ the Blues
(00695608)
HARMONY
Building Extended Dominant Chords
Let’s look at a couple of ways to build on simple 7th chord structures.
First, we’ll build a 13th chord from a 1–7– 3–5 voicing.
A G7 chord would, from the bottom up, consist of the notes G ( 1)–F (%
7)–B ( 3)–D ( 5). The 6th scale degree is one whole step (two frets) above the
5th. The 6th is the same note as the 13th—E in a G chord. If you simply move the D ( 5) on the second string up to an E ( 6 or 13), you get a G13
chord. What makes it a 13th as opposed to a 6th is the presence of the 7th of the chord below the 13th. You can flat the 3rd to get a minor 13th
chord or raise the 7th to make a major 13th chord.
The other chord we’ll build is a dominant 9th. This we will build from the 5–3– 7–1 structure.
Starting with a D7 chord, you move the D ( 1) on the second string up two frets to an E ( 9). Adding the 9th to a 7th chord results in the creation
of a dominant 9th chord. In order to voice a complete 9th chord on the guitar we have to rearrange some other notes as well. The 5th is moved
from the sixth to the first string—two octaves up. Also, we have to move the root from the second string to the fifth string—one octave down. As
with the 13th chord, you can flat the 3rd or raise the 7th to create a minor 9th or major 9th chord, respectively. Look at the following figure to see
the 9th chord variations graphically.
