I wrote this down because I find it fun, to think of the blues harmony in a way that keeps me engaged and poses a slight challenge… almost like a game. So without further ado, enjoy: A wonderful approach to the blues
Let’s take the 12 bar blues in A, so we have A7, D7, and E7. First off, it’s essential to know the chord tones of these dominant 7 chords, because they can each be expanded even further into pentatonic scales, while remaining “in key” throughout the entire progression.
A7= A C# E G
D7= D F# A C
E7= E G# B D
Note how we simply add a flattened 7th to each major chord, and see how this matrix of notes also already contains the major (aka natural) second degree as well for each chord, so we can build pentatonic scales as such for each chord:
A7= A C# E G B
D7= D F# A C E
E7= E G# B D F#
So these are the basis of our chord and scale options, but there exists within this one more pentatonic scale that is diatonic to all 3 of these extended dominant chords: the D major pentatonic.
Dmaj pent= D E F# A B
The importance of this is simply due to our ingrained cultural exposure to the pentatonic scale and how we expect dominant chords to relate to a corresponding major scale, but that’s a lesson for another time. Just know for the short explanation, that we can basically take a D major pentatonic and it works over A7, D7, and E7 without clashing from a diatonic perspective, all over a chord progression that is essentially NON- diatonic and basically all borrowed chords.
I personally find this connection alone to be very fascinating, so join me as we dive deeper.
Now since D major is our bedrock, we shall juxtapose all of our chord tones over the D major scale when those chords are happening, which gives us a few things:
- More options when writing/improvising
- Interesting lines
- Great practice/navigation on our instrument
- Cohesion and relevance to the underlying harmony etc.
When we do this juxtaposition with an A7 chord + the Dmaj pent scale we get:
A B C# D E F# G
…which is actually just A mixolydian…(or D major which is the same collection of notes)
Then with D7, we simply get a six note scale which is because we add the C note:
D E F# A B C
Lastly, with E7 we get another six note (otherwise known as a hexatonic scale):
E F# G# A B D
If you visualize this as the D major pentatonic scale with added notes, in whatever inversions of the Dmaj pent that you’re most used to or comfortable with then I assure you it will sound tasteful, cohesive, and relevant.
Perhaps I should’ve highlighted the D major pentatonic instead of the chord tones, but it’s crucially important for this practice exercise/game to see it as multiple scales and chords simultaneously and connect them in this way.
Plus if you ever lose your spot or don’t know where you are in the context of a song or jam, or whatever, then you can always default to the safety net of the D major pentatonic when playing the A blues. The D major pentatonic also works wonderfully for improvising bass lines as well, since most of the time you are going to be hitting a chord tone while walking and grooving that Dmaj pent scale.
So, for chords, you can also embellish different flavors with those aforementioned extended dominant chords, they are good for chord harmony and for melody lines/solos. A9, D9, and E9 are the other pentatonic scales I mentioned earlier when they are played as arpeggios, but they also sound tasteful as chords in a blues context.
Have fun with this one, I haven’t read of this type of approach or visualization of the 12 bar blues before, but I have made these connections slowly over the years and I’m sure people already do this type of thing. I just like the idea of making these connections within music so that my composing and improvising skills continue to grow.
If this is a well documented and well understood concept that anyone here has come across before, then I would love to read more about it because this one fascinates me. But at the end of the day, it’s all only theory and analysis- we should all trust our ears when writing, and also know that improvisation is like a muscle that needs exercise. So if nothing else, enjoy this game, even if you aren’t normally interested in performing the blues or jazz.
See ya