We learned in a previous article about the benefits of substituting one chord for another. For one, it makes playing rhythm (what guitarists play most of the time) non-repetitive and exciting. Eventually, as we learn more and more chord forms, it makes rhythm playing as thrilling as soloing. As our groovy new harmonic sophistication reaches the same level as those 3 octave arpeggios played at 200bpm, you will never be bored while you float like a butterfly above the rest of the rhythm section.
In this article, we will continue our discussion and dissection of the V chord. As we remember, the V chord’s job is one of tension- we set up this tension to resolve to the I. The good news is that there are more ‘tense’ or ‘dissonant’ chords out there than ‘consonant’ or ‘at rest’ chords.
The m7b5 Chord
We will start with the first 2 chords many guitarists learn, the G7 resolving to the C:
We know that the G7 holds tension, and resolves to the C. In this article, we learned how to build chords in any key. Now if we build 4 note chords from the key of C, we get:
Cmaj7 Dm7 Em7 Fmaj7 G7 Am7 Bm7b5
If we play these chords in order, we get this:
Notice how the Bm7b5 also resolves back to the C? In music theory class, they would call the m7b5 chord ‘half diminished’, but I like ‘m7b5’, since it describes exactly what is in it.
This substitution works because:
The 4 notes in that G7 are G, B, D, F
The 4 notes in a Bm7b5 are B, D, F, A.
These 2 chords are very, very close. In fact, we can consider the Bm7b5 as a G7 with an added 9 (A is the 9 in a G7 chord) and without the root (the bass player is probably playing it anyway).
Our Bm7b5 can replace a G7 at will. So, our G7 to C can become this:
Or, we can say that you can replace a dominant (V) chord with a m7b5 chord ½ step lower than the tonic:
Bm7b5 can replace a G7. Bm7b5 is ½ step lower than the tonic C.
The Diminished 7 Chord
First, let me say, I love diminished 7th chords. It is a rare chord that the relationship between all of the notes is the same: that is, any note can be the root. Here, we will focus on one form of the diminished 7th chord. The cool thing about this shape is that it repeats itself every 4 frets (count the one you start on):
This Bdim7 can also be called Fdim7, Ddim7 and Abdim7. Pretty cool, huh?
The spelling for the Bdim7 is: B, D, F, Ab
It is like a G7 without the root and a b9. But 3 of the notes are the same as in a G7: good enough for me!
Using the dim7 and its inversions, our G7 to C progressions can become:
Like before, use the dim7 chord ½ step lower than the tonic. C is the tonic, and 1 fret below C is B…so use Bdim7 as a substitute for G7 to resolve to C.
The Augmented Chord
This is another great chord that doesn’t get played nearly enough. An augmented chord is like a major chord, with a #5. It reminds me a little of a diminished 7th chord, in that any note can be the root so it can function in many ways. And, if you move it up every 5 frets, including the one you start on, it is the same chord!
Augmented chords certainly have a lot of tension, and one way to use them is to link the I and IV chords. They are usually written with a + after the letter:
How will we use them in our G7 to C progression? Well, imagine C is the IV and not the I. What augmented chord would ‘lead’ to it? G+! To the letters!
G+: G B D#
G7: G B D F
Two letters are the same, I’ll take it! And we can move it around too, so this boring G7-C progression can now sound like this:
Remember to always use the augmented chord with the same root as the V: G+ for G7
Now you should never have to sit on a V chord for very long without substituting another tension-filled chord!
Chord substitutions always sound a little off, and that is the point. Bring that harmony out to left field and then back again- this is how we can manipulate the rhythm, make it less boring for us to play, and more exciting for the soloist, singer or listener.
Maybe the first prominent 7-string guitarist (with a low A!), George Van Eps was a master at harmony. But you don’t just have to use these ideas in jazz- they work in many forms of music.
What are some of your favorite dissonant chords? Who are your favorite rhythm guitarists?