Chord Superimposition - Part 1
Now that we have most of the chord theory we need, we can get into another use of arpeggios in our improvising, commonly called chord superimposition. Knowing all of the different arpeggios and how they are formed allows you to play the correct notes over each chord, but there is more to it than that.
Let’s start with a simple example, a major arpeggio. Start with your C major arpeggio, C, E, G, and look at it as an extension rather than a root inversion. For instance, the C is the flatted third in the key of A, so if you play it using A as the root, you get a b3, 5 and b7, which would be an Am7. By superimposing the C major arpeggio over the A root, it gives you the sound of an Am7. Notice that C is the relative major of Am.
Try the same thing, but this time using Ab as the root. The C is the third, the E is a #5 and the G is a 7. This gives us an Ab maj7#5 chord. You could do the same using A as the root, in which case the C is a #9, the E is a 5 and the G is a b7, giving you an A7#9 chord. You of course have to determine whether the chord is functioning as a major or dominant before you make this type of substitution.
To simplify this, we can make general rules. A major arpeggio built on the third of any minor chord implies a m7 chord. A major arpeggio built on the third of a major chord implies a major7#5 chord. Lastly, a major arpeggio built on the b3 of a major chord implies a 7#9 chord. It is easier to use formulas like this so that you can quickly find what you need for any given chord.
The same can be done with the minor arpeggio. A minor arpeggio built on the third of a minor chord gives us a m7b5 chord. For example, C, Eb, G, using A as the root, results in the b3, b5 and b7, or Am7b5. Built on the third of a major chord you get a major 7 chord. Using Ab as the root, C, Eb, G give you the 3, 5 and 7. Built on the b3 of a major chord you get a dominant 7b5#9 chord. Using A as the root for example, C is the #9, Eb is the b5, and G is the b7.
The same can be done with the augmented triad. If you build on the third of a minor chord you get a minor maj7 chord. Again using A as the root, C is the b3, E the 5 and G# the major 7, which is Am maj7. Use the third of a major and we have a #5 added. C is the third, E the #5 and G#, (Ab), the root. This would work over a major or dominant chord as there is no 7.
Lastly would be the diminished. On the third of a minor this gives us a diminished 7 chord. Using A as the root, this would be C, the b3, Eb the b5, and Gb, (F#), the bb7. Used building on the third of a major chord you get a 7-5 chord. For an Ab root for example, C is the 3, Eb the 5 and Gb the b7. On the b3 of a major you have a 13#9b5 chord. With A as the root, C would be the #9, Eb the b5 and G#, (F#), the 13.
This is just a starting point to give you an idea where to go with the triads beyond viewing them as just triads. Not all of these are practical and your ear should be your guide in all cases. These could, for example, also be superimposed on seventh chords to create even more complex chords, which we will look at next article. The point here is to take what you know and apply it in new and varied ways to expand the range of your improvising. This will allow you to play ideas beyond what you might other wise hear, and expand your ear into new territory.