It not racist just because jazz musicians, by random historical accident, happened to mostly be black.
It is unethical, without any racism, to go looking for excuses to arrest people who play jazz. The proper response is to leave the music venue. Jazz isn't awful enough to merit such heavy-handed tactics.
Seriously, don't assume there is racism under every rock. That is a dismal, pessimistic, miserable, negative, and hateful way to go through life. Bad people exist, yes, but it is terrible to presume the worst out of every unpleasant interaction and terrible to take it as a matter of faith that the world is all about tormenting any particular group of people.
Cheer up. It's good for you. Appreciate the improvement and opportunity.