On Miley, twerking, and brown bodies as white wonderlands

I’m glad this is still around, because I thought this article about the longer history of the appropriation of black culture by white performers, specifically women, was relevant to the discussion. In this case, he compares Joplin and Cyrus (I know, but it makes sense). What do you guys think? Madonna is easy to point to (also, she was appropriating gay culture–anyone seen Paris is Burning?), so is Elvis, but I think Joplin is rarely called out for her use of blues music. Does this transcend the use of black bodies and spill over into black musical forms as well? What are the implications of that? When does cultural borrowing or sharing become racist appropriation, and when is it respectful embrace? And is there any such thing as “pure” music anyway? More popular musical forms (by this I mean across the 20th century, and across genres, as promoted and sold by the recording industry, not in the older term of popular as in from the people, though many popular musical genres came from popular music–maybe it should be mass v. popular?) are hopelessly mixed and fused, with the mixing going all which ways–think Afrika Bambaataa and Planet Rock. What are the differences between that and Joplin singing a Big Mama Thornton song?

BTW - I am not sure aesthetics and tastes is relevant here.