Say you want to play fast 8th note runs on a double harmonic minor song. What note should you add by default?
The Double Harmonic scale has two minor thirds in it. Two common modes of it are the Hungarian and the Arabic minor. The hungarian version is structured W, H, b3, H, H, b3, H
Here is the Hungarian.
The Arabic scale is the same, but played from the fifth. If we consider the Hungarian the Ionian, then the Arabic scale is the Mixolydian. They don’t exactly play the same roles.
If you want to play an eighth note run, you need to decide whether you want to maintain the sound of the two minor thirds or not. If You do, that means you are going to have to split the Whole step. That means H, H, H, b3, H, H, b3, H. In C:
Going back to my 8 tone scales post that is scale #10. There are four half steps in a row, and two half steps between the minor thirds.
By putting the half step right at the begining, it changes where the scale tones align with the chord tones. Assuming you are playing this over a C minor, You’ve just moved the third and the fifth off the downbeat.
If we want to make sure to hit the chord tones on the beat, we want to push the extra note to the end of the scale. That implies splitting the second of the two minor thirds. Adding the dominant seventh is a likely target:
This scale pattern is W, H, b3, H, H, W, H, H. Since I put the Minor thirds at the end in my original post, we can rewrite it as: H, H, W, H, H, W, H, b3 which is scale 22.
This puts the Dominant Seventh on the down beat. If the desired sound is more like a minor/major seventh, you might prefer to use the sixth instead of the dominant seventh.
This is W, H, b3, H, H, H, W, H. Rotating the minor 3rd to the last position: H, H, H, W, H, W, H, b3 is scale 25.
What if you are looking to play a Blues lick? The scale already has a Tritone in it. The minor blues scale is
he example of adding just the seventh is above. Here is what we get if we just add the fourth, and “break” the first minor third:
This is W H W H H H 3 H. Rotated so the 3rd is at the end: H W H W H H H 3 or scale 16.
If we are willing to break both of the minor 3rds, we can cover the blues scale by dropping the Major seventh to a dominant seventh:
This sounds “bluesy” to me.
This is W H W H H H W W. Rotated to H H H W W W H W this matches scale 38.
What about off the Arabic Harmonic Minor scale? Lets put is beside a G Blues scale:
To convert from Harmonic to a Blues,we need to add a Bb, a C# and an F natural. Adding three tones would give us a 10 tone scale, which might be interesting; a chromatic scale minus A and E.
This also seems to have both the minor and blues feel in it. But how could we pare it down to 8 notes? We can drop any of the notes not in the blues scale: Ab B natural, Eb, or F#. All of these notes are make up the minor 3rd intervals that give the scale its distinctive sound. The F# is used in a Mixolydian Bebop scale to make sure the Dom 7th lands on a down beat. The A flat is a b9, often added to 7th chords. This implies we should drop the Eb and B natural, although this decision is a little arbitrary.
This is H W W H H H 3 H H. What is interesting is that it has a minor third, but it is not one the ones from the original scale. Rotating it to put that minor third at the end: H H W W H H H 3 or scale 37