Hey,
Well, what type of fill are you thinking of? A fill is basicly doing something that is different to the original beat in a set space of time.
That opens up a load of different things to do, that could even include just doing nothing!
So what are you trying to do?
Im guessing you mean a roll down the drums (thats a common fill that sounds good and everyone like hearing/doing it). Thats starting from the snare and moving to the high tom, the low tom and then the floor tom (if you have that set up).
Do you mean that? Tell me if you didnt understand any bit of that
