Minor blues progression develops into a few variations which slight deviations usually take place in two common forms.
The first variation is similar to the major blues progression, which uses 4 chords, i, iv, v and V chord.
The chords used (i, iv, v) will transpose into minor 7th chords and then be indicated by lower roman numerals. For the V chord transposing into a dominant 7th chord, which is the same as all chords in the major blues progression. However, the exact chords that will be used are determined by the key of the chord progressions.
Another form of minor blues progression is very similar and equally common as the variation introduced above. This form of progression also features the i, iv and V chords, with V chord on top of it. The 12 bar progression is a bit different than form 1.
Scales and Soloing Over the Progression