The evolution of the truly American style of music known as jazz has been taking place for over a century. During that time, it has gone from a style featuring a single performer to symphonies, from small combos to big bands to rock bands. Each decade of musicians seemed to want to place its own unique stylistic imprint on the music.
Throughout the meanderings of stylistic evolution, several common elements have proven themselves to be the backbone of this musical art form. Regardless of the instrumentation, key, or song form, jazz had had, almost without exception, these essential elements.