The heart of improvisation

The habits of jazz ensure that the most important jazz themes repeatedly become the foundations for the improvisations of jazz musicians. They are played day after day and night after night in hundreds of clubs and concert halls. After one hundred or two hundred choruses, a musician may arrive at certain phrases which then will crop up more and more frequently in his playing of the tune. After a while something like a “standard chorus” on the respective theme will have developed…What was once created by improvising is linked to the man who created it. It cannot be separated from him and given to a second or third musician to play. If this happens, it loses its character, and nothing remains but the naked formula of notes…

In other words, the concept “improvisation” is actually inaccurate. A jazz musician who has created a chorus is at one and the same time improviser, composer, and interpreter…An improvised jazz chorus stands in danger of losing its authenticity and of becoming dishonest and untrue when it is copied by someone who did not create it. Given the multiplicity of human experience, it is inconceivable that the “other” could play from the identical situation from which the “one” improvised his chorus. The relationship between the music heard and the man who created it is more important to jazz improvising than complete lack of preparation. When copying and imitation occur without proper preparation jazz is in greater danger than when, after hour-long, systematic preparation, phrases are created which belong to the player as expressions of his artistic personality…The identity of improviser, composer, and interpreter is what is meant when we speak of improvisation in jazz.

—Joachim-Ernst Berendt, The Jazz Book