Stop, just stop.
I refuse to believe that people were so darn stupid that they had no idea how these songs impacted others.
I understand why you(general you) defend this foolishness. It has to be hurtful to know that your grandparents, teachers, coaches, pastors...people that you loved, respected, admired...were vile, disgusting racists. While they were teaching you(general you) the golden rule, they failed to say that it only applied to white folks.
Now, here we are in 2019 and folks just can't bring themselves to admit that their loved ones were racists. Instead they settle on saying things like the times were different, they didn't know....
I guess pretending your loved ones were clueless idiots ( one would have to be not to know how these songs impacted others) is a lot easier than admitting that they were racists.