Bullpucky. Sacred and secular music evolved alongside one another in the American South. Listen to Pentacostal Holiness music and tell me there's no connection with rock and roll. Elvis loved gospel, and you can hear it in his music. The inflections of Little Richard are the inflections of a country preacher, and vice versa.

And I did not say one led to the other. Linear thinking will not help us tease apart this phenomenon. Instead of A leading to B leading to C, etc., think of music and culture developing and arising together, holistically, if you want to use that word.