“THE JAZZ AGE” refers to the decade after World War I, when the nation became predominantly urban. It took its name from the rich and varied new popular music which was essentially a creation of the Negro in the city. Historians cannot agree on the origin of the word “jazz”: some say it is of African or Creole origin, and others say that it derived from the name of a musician. But there is no denying that this American form of music originated with Negroes in the first age of their migration to the city, and jazz flourished primarily because of the talent, energy, and imagination of Negroes in cities. In Europe, too, the years after World War I were an age of musical experiment. But jazz was a more democratic, more communal kind of experiment. For the old World saw developing novel forms of “art music”, of salon and concert-hall music.