Well, I agree with Allen 100% regarding Lou Donaldson.
However, I find the whole question of authenticity in black music (and that category includes white players playing black music), along with its assumptions about class, is a slippery slope full of questionable assumptions that I had thought were put to rest ages ago. I also think that third parties judging the "authenticity" of other artists is just plain bad form. I'm not talking about aesthetic judgments, I'm talking about something that almost takes on a dimension of moral reprobation.