I do think that everyone in the world can understand art honestly, we all have different views of things, like the Mona Lisa for instance. Some people think shes smirking and others think shes frowning. Depending on who you are and how you think defines the way you look at art.
Why might African American artists such as Langston Hughes reject the playing of the blues by white artists like Bob Dylan and the Rolling Stones? It disconnected the music from the social conditions in which it was grounded.