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        The jazz is before a a whole music of division, an orchestral music, a music of friendship. 

The time is far where in the unconscious collective from the public the jazz music summarized in “Oh when the holy go marching in” even still with the “Negro Review” of Joséphine Baker. However, even if the jazz evolved much since it does not remain less true about it than it kept its characteristics essential to know the rhythm and the improvisation.

 

        Improvisation was a current practice in the musicians of formerly. Time of Bach the least executant could improvise during a piece. This practice disappeared since in the classical music, or to be exact, in the romantic music.
 
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Duke Ellington
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        The jazz changed style has each decade After the Thirties, at the time known as of the “swing” one noted already the presence of serious troublemakers within orchestras like that of Ellington, which announced the harmonic and rhythmic audacities bop with its tempi very fast, its harmonies which skin the ears accustomed to pleasant sonorities of the melodies of varieties.

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