I only learned about that song a few years back. Terrible stuff has happened in living memory. I'm just reading a book about black people in Virginia where they could not use the same hospital as whites in the 1950s. There were all sorts of crazy laws that affected musicians. I think Billie had to darken her skin sometimes as some people might think she was white and then it wouldn't be acceptable for her to play with a black band.
I grew up with loads of West Indian, Indian and other nationalities in Bedford, but as a white kid I couldn't appreciate the abuse they would get all the time. We were just kids who played together and it wasn't discussed too much.
Things may have improved now, but the fact that Black Lives Matter is a thing shows it could be better. Of course 'all lives matter', but they should matter equally.
RE: Billie Holiday and Strange Fruit