Another one of my posts didn't make it through the ether. To sum it up:

"Minor" is more likely to entail "plaintive" than "plaintive" is to entail "minor." "Plaintive," at least as I understand it, could cover minor, modal, and (hypothetically) blusey.

Guesswork: an early 19th C. writer hearing a blues scale and perceiving it as systematic rather than accidental (i.e., sung by someone with a tin ear) would have used words like "weird," "wild," or "savage" to describe it. Otherwise the words would be more like "out of tune," "off-pitch," "flat," "discordant," etc. ISTR "wild" being used in at least one description, though I suppose it could just as easily refer to timing as to tonality.

How far back does the blues scale go? Did it originate in Africa before 1800? Or do we know?