Also, what’s some good blues music?
The most common 2 keys for the blues on the guitar are easily E and A but it is a little more complicated than that. You can play a minor blues, major blues, and even modal blues (which is really kind of getting into jazz)
In the blues they use major or dominant seventh chords mainly for the I, IV, and V chords instead of minor chords that are normally used in a minor key. This is the most common blues SOUND. It is really kind of a hybrid of major and minor qualities. The blues scale’s minor chord tones conflict with the major chord tones in the chords and create a pleasing dissonance.
So my answer would be E major and E minor though it is more easily understood as a minor key.
(some have gone as far as to analyze each chord of the I7, IV7, and V7 progression as being dominants [V7] of 3 different keys. E7 – use A major scale A7 – use D major scale B7 – use E major scale)