We also cannot leave out the Aboriginal American people's influence. There is a movie called Rumble on netflix, that goes into this aspect of american music. I think you would enjoy. It does get in to the vocal harmonies, but not in an academic way.
I mean not that T.W. wasn't huge, but it is difficult to hear any Chinese influences in his style.
re a blues scale:
I been messing around this morning on guitar. If I had to make a scale for the blues, I would make it
i, ii#, iii, iv#, v, vi, viib
sort of a harmonic minor vb?
I'm on vacation, and got time. I think I will search this out in the Thesaurus of Scales and Melodic Patterns.
Miles (iirc) wanted to apply Japanese visual design concepts to his sound.
Say what you will about the old USA, we got some fine music going.