Chord Superimposition - Part 2
In the last article, we saw how superimposing a triad over a root note allowed us to build many of our seventh chord types. What this demonstrates is that many of the more complex chords are just triads superimposed over each other. By learning some simple formulas, you can then come up with some interesting lines that extend the chords that you are improvising over.
Let's take a major ninth chord as an example. Cmaj9 consists of C, E, G, B, and D. There are two approaches you can take to looking at this. One is that the upper notes spell out a G major triad. Another is to look at the top four notes, which spell out an Em7 chord. The point here is that you need not only use triads, seventh chords can also be used in this manner. The formula here is that a minor seventh chord built on the third of a major chord gives you the notes of a major nine chord, less the root.
Now let’s do the same with a minor ninth. For Cm9 we have C, Eb, G, Bb, and D. Once again, if we look at the top three notes, we have a Gm triad. The top four notes will give us an Ebmaj7 chord. In this case a major seventh built on the third of a minor seventh chord gives you the notes of a minor ninth chord, once again, less the root. Notice that you get a major seventh on the third of a minor and a minor seventh on the third of a major. For jazz pianists, this will look familiar as this is how you form your rootless voicings.
You can use this same thinking to deal with dominant chords. Taking a C9 for example, we have C, E, G, Bb, and D. The top triad is a Gm again, as it was for the minor nine. The minor triad then works for both the minor and dominant nine chords. Looking at the top four notes, we have an Em7-5 chord. The formula here then is to play a m7-5 arpeggio built on the third.
For the eleven and thirteenth chords there are the same options. A C11 chord would contain C, E, G, Bb, D and F. The top three notes give you a Bb major chord, the top four a Gm7 chord. Try the same with the notes of a thirteenth chord. For every type of chord, you can find a formula like this to make it easier to have a starting point for your ideas.
The same applies to altered chords. As an example, we will use C9#11. Our chord consists of C, E, G, Bb, D, and F#. The top three notes spell out a Bb augmented triad and the top four a Gm Maj7 chord. You can do this for all of your altered dominant chords to give you simpler formulas than memorizing each type of chord one type at a time. This type of thinking gives you a "common denominator" for every chord type, allowing you to play and not think so much.
How this applies to improvising is that you can use it over a compatible chord to extend it in your solo line. For example, any major seven chord can be "extended" in this manner by playing a minor seventh arpeggio built on the third. To the listener this gives the sound of a major nine chord, even though the accompanist is playing a major seventh chord. Try it with your other chord types where appropriate, (make sure you do not conflict with the key, except of course for dominant sevenths), to extend the chords of the harmony.
Just as we did in the last article, we are learning to take smaller chords that we know and use them to understand and play over what at first appear to be much more complicated chords. Most seemingly complex chords can be reduced to much smaller pieces that you already know, which will allow you to spend more time in the creative process and less time analyzing and trying to figure out what to play. The smaller chords will help you to hear the extensions of the larger chords, helping to train your ear and, as is the goal of these articles, play what you hear.