Here is a link to a three-minute clip from a documentary from the 1965 Newport Folk Festival where the blues singer and guitarist Son House talks about the nature of the blues.
Here is the URL to the video clip posted on YouTube.
He says:
The Real Old Blues don’t call for no jumping. If you go to jumping, that ain’t the Blues. They can name it the Blues, but it ain’t the Blues.
What does jumping mean in this context?