isn't this simply because black artists that preceeded hendrix (and white artists too), made it that way and it was "wedged" and had a firm grip on society already? That the model for music itself was to make people dance, and not move them maybe cerebrally, as an artist like Hendrix could do?
Could a statement also be made that the movements of a flower child spinning and waving his/her arms in a field listening to "Purple Haze", is also dancing?
To make the argument that any music that is going to appeal to a majority of black listeners has to be dance, would cause many to assume that black people are the only race with dance in their history. When the truth is that most cultures adopted dance far enough back in time for it to be "in their blood" so to speak...
You could also say that the Latino culture is also based around dance as a preferred form of music, though some of their biggest and most popular artists have been, and continue to be, straight up rock.
I say all this only in debate...
There are a few points to make here. First, it is a dangerous assumption to make dance music cannot also be thought provoking. Curtis Mayfield, Stevie Wonder, War, and others made lots of cerebral music with a good beat. As for a flower child waving arms, by Black standards, that is not dancing at all!
I never said that Blacks are the only people to dance in history, but dancing is central to the way music is experienced by the black masses. Your examples of Latino culture actually reinforces my argument because all of the great Latin dance music has African roots that are even more undiluted than much of African American music.

