465. THE MAJOR-MINOR INDIFFERENCE RULE IN (12 BARS) BLUES IMPROVISATION

 According to this rule, the melodic improviser so as to improvise may assume either a major or a minor or both  scale over the 3 chords of the blues.

https://www.youtube.com/watch?v=C8EAAVxvB4A&ab_channel=JamesHargreavesGuitar