New Orleans, where jazz evolved from polite dance music into feral stomps, was a colorful confluence of European and Caribbean cultures when "hot jazz," a.k.a. Dixieland, arrived on the heels of ragtime in the early 20th century. Black musicians like Jelly Roll Morton and Buddy Bolden were already improvising and swinging hard when the all-white Original Dixieland Jazz Band popularized the term "jazz." Clarence Williams, King Oliver, and Kid Ory set the style afire, playing portable, non-chordal instruments originally used in marches. Oliver wisely hired the teenaged Louis Armstrong, who proved an unstoppable force when the music moved north.