The broadly widespread emphasis on pentatonic formations arrived mostly from West Africa, While the diatonic (and later on more chromatic) melodic strains of jazz grew from late nineteenth- and early twentieth-century European antecedents. Bebop emerged during the forties, shifting jazz from danceable well-liked music toward a tougher "musician's music" https://jazz55666.idblogmaker.com/31947509/the-smart-trick-of-morning-jazz-that-no-one-is-discussing