As I have discussed in previous posts, traditional harmony/theory constructs chords in intervals of a third. There is another type of chord construction that is quite common in jazz, called “quartal harmony” or sometimes better known as “4th chords.”
Quartal harmony is most commonly associated with the modal jazz of the late 1950′s and 60′s. For those of you who have ever heard the greatest jazz recording ever made – Miles Davis‘ Kind of Blue – you are already familiar with the sound.
Quartal harmony and 4th chords translate extremely well to the guitar, making anyone who plays them an instant multi-platinum record selling artist and put on the Grammy short list. (It’s true, just ask Lil’ Wayne; he’ll tell ya.)
Let’s hip ourselves to a little modal jazz and quartal harmony, shall we?
One of the great aspects of 4th chords is their slightly ambiguous/rootless quality. Because they don’t contain any tension notes such as the 3rd and 7th in a traditional chord, they have something of a more mysterious and aloof sound to them (to my ears, anyway). To form 4th chords, simply stack a chord using intervals of a 4th. Here is what they look like in D:
Now, I’m hoping you played through this example before continuing to read, because I purposely threw a wrench into the works. Did you figure out what it was? If not, please go back, play through the chords, and think about the concept for a minute. See if you can figure it out. It’s a great exercise for your brain.
You should have noticed that some of these chords are not built in perfect fourth intervals. The third chord, for example, has the notes Bb to E, which is a tritone/augmented 4th, not a perfect fourth (which should be Eb). So why are we not using perfect fourths? The answer is because we’re playing music, not engaging in theoretical discussions about music. You always have to keep in mind that it has to sound right just as much (if not more) as be right from an academic standpoint. If you are playing a quartal harmony vamp in ‘D’ the Eb will probably not sound very good. Sometimes it will, sometimes it won’t. It’s up to you to figure out what is appropriate and go from there. In most modal songs the E natural note will most likely sound better, so your chord will include the tritone from Bb to E and then stack the ‘A’ note as a perfect fourth above ‘E’. Read that again if it doesn’t make sense, especially the part about playing music.
Quartal Harmony Comping
Now when we comp, as mentioned in several other posts, we don’t necessarily want to play thick chords with lots of voices. This muddies up the music and makes it difficult for the soloist to stretch out. For that reason, we can remove the root voice of each chord and only play the three upper voices, like this:
The sound is essentially the same, but it breathes a little better.
One very cool feature of these chords occurs when you start to use inversions. By taking the bottom note of each chord and transposing it up one octave, you create some very hip chord voicings that you can use in your comping.
Definitely play these voicings over a ‘D’ bass vamp and listen to how they sound. The 2nd intervals sound great to me, very pianistic in nature. You can also experiment with a second inversion, moving what is now the bottom note up an octave as well. (Figure this out on your own, folks. I want to keep your brains actively working.)
You don’t have to only play these chords over modal tunes, by the way. These chords also sound great as substitutes for many minor chords, especially minor 11 chords. Again, let your ear guide you; if it sounds good then use it. If not, modify it. If that still doesn’t work, throw it out and do something else.
That is, in a nutshell, the concept of 4th chords and playing quartal harmony. I suggest you get some modal playalong tunes (or use Band in a Box) and go to town for a while. Also experiment with moving voices in each chord so you’re not just clunking chord after chord. If you have not heard Kind of Blue, buy it and absorb it. If you don’t know who McCoy Tyner is, now is the time to start thinking about non-guitarists for a spell.