M. Ted.

I disagree with your statement that minstrel music was this was "all entertainment--written and performed to entertain, to get laughs, etc--it was created without any sense of what any deeper implications might be, and certainly without any sense that it was hurtful, in any way"

It is an African American tenet that there is no such thing as 'art for arts sake". Like the Deep Throat quote: "Follow the money", one important line of inquiry is how is the art used?

Or let me say it this way if indeed "this stuff wasn't intended as any sort of tool for racial oppression" it became a tool of that oppression. And the stereotypes of Black people that were promoted by Black faced ministrels {be they cork wearing White people or Black people who put cork over their brown skin to make a living in show business} still live on.