Superimposition is the process of layering one tonality on top of another to suggest an entirely different tonality.
Superimposing tones is often used in Jazz and Classical music to give a more sophisticated and often 'outside' sound to the songs. Below we'll examine just what exactly it is and how you can learn this yourself.
First, let's say we're playing in C major:
Next, let's say we play a Cmajor 7 chord, nice and easy:
Now, the keen eyed will have noticed something.
The 3rd, 5th and 7th degree of the Cmaj7 chord form an Eminor chord.
So, if we play an E minor triad over a C backing, we can easily suggest a major 7 tonality. That's all there is to it!
We're playing one chord (E minor) over another (C major) To suggest something else (C major 7). Not only does this have the benefit of being able to confuse newcomers, but we can also do something actually useful with it!
Now, personally I find improvising over m7b5 chords to be somewhat tricky, so what I would do is analyse the notes of a m7b5 chord and see what other chords I can deduce from it.
Let's take an example using Am7b5:
Now I don't know about you, but I can quite easily see a C minor triad in there (C, Eb, G). To poor improvisor Joe this is a good thing, it means instead of having to remember 7 notes (A locrian scale), he only has to remember 3 (C minor triad).
A word of warning: Exclusively playing superimpositions as I show above will get boring. Admittedly there is only so much you can do with 3 notes (and don't let any blues player convince you otherwise!).
Below we will examine some more fun things to do with superimposition so you can get a bit more mileage out of them than what is shown above.
Getting more from superimposition
Another thing to do with superimpositions is to work backwards with the chord.
For instance, Let's take a G7 chord, a G7 consists of the following notes:
With dominant chords, you are given much more leeway as to what notes you can play. Altered tones are very prevalent over dominant chords, especially in jazz. So, let's look at ways that we can superimpose some of these altered tones over our G7 to make for a more interesting improvisation/musician!
Let's say (for whatever reason) that I want to emphasise some altered tones of the dominant chord.
Now for this, we're going to go a step up from imposing a chord over a chord like we did in the first section. Superimposition is just playing one note over another to suggest something different, so that's exactly what we'll do.
For our example we will need to go one step ahead and instead of superimposing one chord on top of another, we will be superimposing a pentatonic scale.
Like I said before, we are working backwards. Now let's begin.
We said before that we want to work with altered tones. The main altered tones are:
Fortunately, we can get all of these tones and more with just one pentatonic scale!
The Bb minor pentatonic seems a suitable fit.
Now that we have all of our altered tones, we have some things that will work very well within a dominant chord.
The b3rd is the enharmonic equivalent of a #9 (an altered tone)
The b5 is one of our altered tones
The b6 is the enharmonic equivalent of the #5 (another altered tone)
The b7 is a chord tone of the dominant 7
The b9 is another one of our altered tones
With this knowledge, we now know that we can play a Bb minor pentatonic over a G7 to add an altered tonality to our playing. Let's try and sum this up to something more general;
Playing a minor pentatonic a minor third above the root give us an altered quality by yielding the intervals - #9, b5,#5,b7,b9
That is much easier to understand. Now we know to play a minor pentatonic a minor third above the root and BOOM, instant jazz.
For those of you wondering how did I find that one suitable scale out of a plethora of scales? Well unfortunately it's just a lot of trial and error, I've gotten pretty good at narrowing down results and I don't know one magic way to deduce a good superimposition. Music is allllll about experimentation!
Before I finish off, let me just give you a few more possible useful superimpositions to keep you busy
A major triad a tone above the root gives a lydian quality by yielding (2,#4,6)
A major triad a major third above the root gives us a M7#5 by yielding (3,#5,7)
A minor triad a semitone above the root gives us an altered quality by yielding (#9,b3,#5)
A minor triad a minor third up gives us a m7b5 by yielding the top 3 notes of a m7b5 chord.
A minor triad a major third above the root gives us a M7 quality by yielding (3,5,7)
A minor triad a semitone below the root gives us a lydian quality by yielding (7,2,#4)
A minor pentatonic a semitone below gives us a lydian quality by yielding (7,2,3,#4,6)
- An augmented triad a semitone below the root gives us a mM7 quality by yielding (7,b3,5)
There are many more possibilities, and this is more than enough to get you started in the wonderful world of imposing stuff on top of stuff to gain stuff. If you come across any majestically beautiful impositions, let me know! E-mail me some of your favourites, I love to nerd over music :D