Thanks for the article, Jack. Did you read it? He takes issue with your viewpoint rather vehemently:

"Nothing is more absurd than the balderdash so common amongst Crow Jim French and British critics, that jazz is "the voice of the downtrodden Negro people...jazz itself appears first as part of the entertainment business, and the enraged proletariat do not frequent night clubs or cabarets"

He also points out, in several places, that jazz music was feature in Broadway shows of the twenties--and, in point of fact, George Gershwin both played and wrote jazz--Many of his songs have been turned into silky cabaret ballads, but were hard driving jazz numbers in the original shows--Berlin, Rodgers and Hart, and the rest wrote songs for the times, it was, after all, "The Jazz Age"--