All I know is that most of my teachers throughout the years rocked. Sure there were some that were over weight. Those are the ones that were said to Rock and Roll.
Teachers can and should be whatever they like, as long as it doesn't set a bad example for their students. If they can't be rockers without setting a good example, then maybe they shouldn't be teaching.
"Those that can, do and those that can't teach."
I'm not sure if the quote is correct. Music's Key Role in Helping Students Learn