You cannot state 'your' definition of Jazz, and then have a discussion with others, using 'your' definition as a given fact. What you found lacking in the bluegrass piece, even by 'your' definition, was a matter of degree, judgement or opinion.
The Herbie Hancock piece was not 'muffled' due to the quality of the recording. The music was muffled because it had no dynamic range. The difference between the highest and lowest notes. Booker T and the MG's come to mind. Maybe Herbie Mann? That type stuff. Memphis Soul. Not James Brown as you mentioned.
The music landscape is littered with musicians who possessed the following attitudes: 'understanding' their music or 'getting it' was solely the job and responsibilty of the listener. "take it or leave it". "You don't understand what I'm saying? Well that is just a reflection of your lack of musical understanding" etc......
I would name them, but they are unknown.:)
Bet you can find them on every street corner in NYC. If the artist does not connect with the audience, HE/SHE has a problem! Just a variation of 'the customer is always right'!
Whenever I see the name of a so-called genre with a hypen, I always ask, why is that needed?
Other than these small and insignificate differences, we are in total agreement.
Cheers