And also there are many kinds of fills that can be useful per variation

1) a stop filling: the drums comes to conclusion stop strongly and quickly...and as long as you continue pressing the filling it keeps the stop.

2) syncopated or groove filling: the filling is syncopated or of different groove and as long as you continue pressing the filling keeps at that groove.

3) filled power filling: the drums fills the piece completely and the longer you press the longer it is.

4) regular fillin that comes with the keyboard.