Introduction
In this lesson we will explore a simple idea, that your improvisation should reflect your chord progression.
- So if you chord progression increases tension, then your improvisation should also increase tension.
- So if you chord progression resolves tension, then your improvisation should also resolve tension.
- So if you chord progression uses chromaticism, then your improvisation should also use chromaticism.
- Etc.
There are four ways to use chords from a different key without changing key. These are:
Chromaticism & Improvisation
If the chord progression uses of these techniques then it has used chromaticism and has NOT truly modulated to a new key. When this happens you can do one of three things with your improvisation:
- Change keys in your improvisation;
- Do not change key and simply play over the top of the foreign chord with your existing scale;
- Do not change key but modify your existing scale to account for the Guide Tones of the foreign chord.
For example, let’s say we have the following chord progression.
This chord progression is all in the key of C Major. However it has the following chromaticisms:
- The A7 is a secondary dominant tonicising the Dm7 (highlighted red);
- The D♭7 is a chord substitution of G7 (highlighted blue);
- The Fm7-B♭7 are borrowed chords from the parallel natural minor (highlighted green).
Let’s go over each of the three options in a bit more detail.
Option A) Change keys (not recommended)
You could change key to the appropriate diatonic scale. This approach is not recommended because the improvisation does not reflect the chord progression. It ignores that fact that the chord progression hasn’t modulated. Now, of course, it sounds fine and you can use this approach, but it’s a bit of a lost opportunity. This kind of approach is pretty standard and as such can eventually sound a little bit boring and expected.
Option B) Play over the top of the foreign chord with your existing scale
Alternately, you could just keep playing the C Major scale all the way through this progression without worrying about the chromaticism. So we are just ignoring those foreign chords. This is an ok approach to take. You’re going to hit some unpleasant sounding avoid notes, but that’s ok, at least your solo is reflecting the chord progression by not changing key. The fact that you’re improvising with a single scale all the way through will give you solo some consistency and structure.
Option C) Modify your scale to account for the Guide Tones of the foreign chord (recommended)
Finally you could play the C Major scale, but alter some of the notes to account for the chromaticism. This is done by sharpening or flattening one of the notes in the C Major scale to take account of the guide tones of the foreign chord. For example, the guide tones of the chord A7 are C# and G. G is already in the C Major scale, but C# is not. Therefore, over this chord, we can plat the C Major scale, but with a C# instead of the note C. Below are the scales we can use for each of the foreign chords in this progression.
Selecting Scales
As we have already seen in an earlier lesson, you can use a particular scale to play over a particular chord if that scale contains the 3rd and 7th of the chord (the root is less important). The guide tones are the 3rd an 7th of a chord and are the most important notes in the chord because they determine the quality of the chord (whether it’s Maj7, min7 or V7).
While any of the above approaches to improvising over this progression can work, the last one is recommended because it keeps most faithfully to what is happening in the chord progression. We are not change key here, we are simply using chromaticism in our harmony to make the progression more interesting. As such, we should not change keys in our improvisation, instead we should similarly use chromaticism to mirror and adhere to the harmony. And because the Guide Tones are the most important notes in a chord, the scale which we use to improvise over them should reflect this and not clash with the harmony.
Synthetic Scales
This required us to create synthetic scales that we could use over the foreign chords in this chord progression. A synthetic scale is a scale that is derived from the Major scale but has had one or more notes altered by a semitone. Notice that these synthetic scales are actually already existing scales with conventional names. This need not always be the case. You may create a synthetic scale that does not yet exist and thus does not have a conventional name. So, in a sense, these synthetic scales are often just another way to think about modes and how to map particular scales to particular chords.
Having said that, Option B is also acceptable. Some of the notes in the C Major scale will clash with the foreign chords, but that’s ok if you treat them as either Avoid Notes or as notes that build tension. But a good rule to follow when improvising is: when the harmony changes key, your improvisation should change key; when the harmony uses chromaticism, your improvisation should use chromaticism.