Yeah, I know, cheesy joke. But this statement does remind me of something my high school band director told me.

Mr Zavadil was the greatest teacher. He held the respect of every single one of his students and he almost never had to raise his voice. Well one day I stayed after class and was talking to him and he let me in a little secret of his. He told me that when ever he found a student who was getting out of control he would pull the student aside and talk very quietly with him. When he did this every other student in the room would be staring at the two of them, dying to know what was going on and of course supposing the worst. But the thing I remember the most about Mr.Z is that because he hardly ever yelled at anyone when he did, we were shocked and we knew we had really ticked him off.