Gary, there's no such thing as wrong. It's true that there are many similarities between Black gospel and the type of traditional southern blues usually associated with Black musicians (note that 'Black' is normally capitalized when used to identify race - same with 'White', otherwise it's just a color). As far as Eric Clapton goes, yes, I would certainly consider him a creditable blues performer - but you were asking about the music, not the performer. I believe anyone can play or sing the blues, but I think those steeped in the culture are likely to sound more authentic. Good blues requires 'soul' and not everybody seems to have it (or even recognize it when they hear it). Joe Cocker, one of my all-time favorite singers (if you can call him a singer), had soul to spare, Pavarotti had soul, Janis Joplin had soul, Maria Callas had soul, James Brown had soul, Ray Charles had soul, Aretha had soul, etc., etc., and the list goes on.

The problem with labels in music is that too many different things are lumped under the same label. A true musicologist could do 5 Phd disertations on 'The Blues' and still only scratch the surface. There are social aspects, historical aspects, musical aspects.....the list goes on. Not a simple definition for it, for sure but I'm heartened by your interest since it's one of my favorite musical forms (when performed at a high level). Because of the cultural makeup of this particular forum, there probably is not much interest here but it, along with an evolutionary form of it, Jazz, ARE considered to be America's only true original art form.

chas