The article you cite does not refer anywhere to the "fear of Black jazz musicians".
Political propaganda in the 1930's was no less malevolent, no less maligning in misattributions than today's politiks.
E.g., John Kerry's sworn testimony before Congress accusing the U.S. military of "committing atrocities everyday" in Vietnam. Another example, Bush-Bashing assertions that Bush doesn't care about the poor and the Black.
However, all assertions maligning Hillary Clinton and George Soros are quite true and appropriate as a warning to American citizens. : )
Political propaganda in the 1930's was no less malevolent, no less maligning in misattributions than today's politiks.
Are you at all famililar with the history of marijuana prohibition in the United States?