You're right, Martin: I think some of this is a generational thing.
I wouldn't expect to find as much interest in bluegrass among southern blacks these days (although they may have more of an interest in country music because there are at least a handful of black country performers. And most young blacks (and many, many young whites) are so into rap and hip hop with a strong beat and contemporary urban concerns that I can't see how they'd be attracted to bluegrass, string band music or folk. Some of it is probably an urban/rural thing, too.

You're right too, Susan. The musical separation (not to use the word segregation) does reflect different cultures and interests (and tastes.) At the same time, it's hard to say that certain groups of people don't like a particular kind of music if they're rarely heard it. I hear groups like Black Eyed Peas who I suspect would like some of the old black jug band and string band music... if they haven't already heard it. Most younger blacks (under 50) give me a polite, but somewhat blank expression when I tell tham that I sing folk music. Some take the bull by the horns and say "what is folk music?"
And they aren't struggling to come up with the definitive definition. They have no idea what I'm talking about. I've found that when they hear it, and understand better that it includes blues and gospel, many of them enjoy it. They just don't hear it. Not that anybody does, other than us people who were immersed in it, in the 60's and 70's...

Jerry