Improvisation is the most important element of jazz styles in general. Drum set players should be as comfortable with improvisation as the rest of the ensemble. A common kind of improvisation within a song form is to “trade fours”. This means that the various members of the band take turns improvising four measure sections. The drums usually alternate back and forth with the rest of the band. The drummer should be aware of the form of the song and pace their playing to shape the performance appropriately.