That was back in the ‘30s, and it didn’t start then.
Edit. Anslinger was the head of the Bureau of Narcotics, which eventually became the DEA. (At the time, most (all?) famous jazz musicians were black:
> Anslinger looked out over a scene filled with rebels like Charlie Parker, Louis Armstrong and Thelonious Monk, and—as the journalist Larry Sloman recorded—he longed to see them all behind bars. He wrote to all the agents he had sent to follow them and instructed: “Please prepare all cases in your jurisdiction involving musicians in violation of the marijuana laws. We will have a great national round-up arrest of all such persons on a single day. I will let you know what day.” His advice on drug raids to his men was always simple: “Shoot first.”
He reassured congressmen that his crackdown would affect not “the good musicians, but the jazz type.”
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.