How did we get here?

How did we get to the point where certain singing voices are racialized? Everyone I’ve spoken to (and me too) was surprised to discover (a few years ago) that Adelle was not black. Now it’s happening all over again with Meghan Trainor and “All about that Bass”. I’d heard the song at the gym and looked for the music video, when Ms Trainor appeared I was shocked. As was my wife when she walked into the living room. I’ve polled a bunch of others in the office and they were all shocked as well.