Jun 05 2017
Intro to Drop 2 Chords - (Part 2)
By: Michael Odell
Posted in: Jazz Guitar Lessons
In this further exploration into the use of drop 2 chords we’ll look at a simple way to add tension to the V chord in a Major ii-V-I progression. We’ll continue using the drop 2 chords on the top four strings as was covered in part 1 you can find here.
In the key of C the V chord is a G7. Dominant chords are inherently tense because of the tritone interval or b5 interval that exists between the 3 and b7 of any dominant chord. We can add more tension to the V chord to create a stronger pull to the I chord which creates a stronger resolution. The addition of chromatically altered extensions such as the b9, #9, b5, and #5 to the dominant chord will increase the tension because the altered chord tones are not part of the key.
There are two primary ways to add tension to the V7 chord: 1.) alter the dominant chord itself by adding the altered notes or 2.) substitute the dominant chord with another chord that will provide the desired altered tension(s). In this case, we’ll substitute the G7 with an Ab diminished 7 or Abo7.
Substituting Abdim7 for G7 to our ii-V-I progression in C gives us:
Even though we are substituting an Abdim7 chord, it is functioning as a G7b9. If you compare the two chords shown below, you will see that the Abdim7 contains all the notes of the G7 chord except the root. In other words, the Abdim7 contains the 3rd (B), 5th (D), and b7 (F) of the G7 except the root. You move the root G up a half step to Ab which makes it a b2, the same note as a b9. An Abdim7 chord is the same as a G7b9 chord without the root. In a band situation, the bass player would be playing the G note creating the complete G7b9 chord.
Diminished 7 Chord Structure
Looking at a close voicing of a B diminished 7th (same as Ab dim7) chord below, you will see that it is constructed by stacking minor 3rds. The chord spelling is Rt-b3-b5-bb7
Since the intervals that make up the diminished chord are identical, it is known as a symmetrical chord. Any one of the four notes that make up the chord can be considered the root. Another great attribute of symmetrical chords is that you can move the same shape up or down the neck in minor thirds. The close voicing is difficult to play due to the large stretch. The voicing we are using in our ii-V-I progression is a drop 2 shape, much easier to play. Here are the drop 2 Ab diminished 7 chords you can use to substitute for the G7.
Abdim7 in four locations
Here’s another example using the Ab diminished 7 substitution using all drop 2 chords on the top four strings in a ii-V-I progression. Example 2f.
We can use the symmetrical nature of the dim7th chord to move around the neck and end on the I chord to create some drama but don’t over use it. Here’s two examples, one moving down the neck the other moving up. Example 2g.
I’ve given you two positions of the ii-Vb9-I, ex. 2b and 2f. Try to work out the other two on your own. If you need a refresher check out part I. Good luck and in part three we’ll look at using chord substitutions to add the natural 9th extensions to the ii-V- I progression.