If we were to include the entire 20th century, it would undoubtably be Al Jolson, whose role in helping define 20th century American music is largely forgotten.

It was the Jews and the Blacks in America who, at the turn of the century, ushered in an evolutionary change in music through jazz and pop. If it weren't for folks like Jelly Roll Morton, Irving Berlin, Al Jolson, Bing Crosby, Satchmo, W.C. Handy, etc., there wouldn't be a Frankie, Elvis, or Michael Jackson. Crosby repeatedly said throughout his career that Jolson was his idol.