The Greatest Musician of the Post-World War II Era

What kind of insane musical culture do we live in when an “eminent rock critic” (as described by the New York Times) can refer to James Brown as “the greatest musician of the post-World War II era”? It seems to me this was also a period in which Stravinsky, Miles Davis, Charlie Parker, and Leonard Bernstein were all at work, to pull a few names from a hat.