Brutality to an animal is cruelty to mankind - it is only the difference in the victim.
I think you have to control the materials to an extent, but it's important to let the materials have a kind of power for themselves; like the natural power of gravity, if you are painting on a wall, it makes the paint trickle and it drips; there is no reason to fight that.
So when you enjoy the beats, the rock music - maybe even toned down with an orchestra - you are enjoying the spirit of the black race. And that's what I emphasize to the students.