I’ve been here for 6 years and I’ve heard ‘boy’ used a couple of times that have made my skin crawl. Prior to being in the south I had seen it used like that only in movies, so I don’t think I fully understood the gravity of it, or that that this sort of thing still happened.
Some older southerners will use it to refer to groups of younger people white or black, but when directed at only black people/person and said in that tone (a tone that the Jazz fan mimics) it is incredibly racist.