Is there an association between the major scale and the blues?

[Earthday]

I just realized that the only three major chords found in a major scale are I-IV-V, aka, the blues. But only the V has it's b7 included in the scale. But IV's b7 is the Minor 3rd of the root, and I's b7 is the minor 3rd of the V. Is this the foundation of your typical blues progression, or am I thinking too hard? Is it okay to use the minor 3rd of each individual 7 chord, or is it generally only a good idea to use it with the I? Should I stay away from major 3rd of the V since it is the major 7 of the root?

This is all assuming a typical I7-IV7-V7 progression.

[HaVIC5]

The blues has its own sort of harmony associated with it that is unique to the blues. It exists somewhere in between minor and major, and has a bit of other stuff thrown in. The short answer is, the only true "blanket" scale that you can use over all the progression is the minor pentatonic blues scale, otherwise, you have to think in terms of each chord. Since every chord in the blues is a dominant, you can have both the major third AND the minor third (technically #9) over ever chord. You could think of them all as taking mixolydian scales, but with the second degree sharped. The #9 on the IV7 is kinda iffy, but it works if you know how to use it right. There are other ways to look at it, but if you alternate between chord tones and minor blues scale, you have a pretty authentic approach to the blues.

This is to say mainly that the blues is NOT derived from the major scale, so you can't analyze it that way.

[Earthday]

Thanks, that makes sense. When you visualize the blues scale do you think of it as one scale, fixed in one spot regardless of the chord you're on? Basically a bunch of universally usable passing tones? Would you think of it in terms of the chords it includes?

[Thor]

A useful way to look at is is how a harmonica player does.
They play 'cross harp'.

Blues in
I-IV -V E - A - B uses an A harp.

A -D -E uses a D harp.

[MichaelScott]

Play dominant scales.


Unless you are doing Jazz blues.