One way I could throw out a “smart” answer is to say – the one that hasn’t been coined yet. Let’s face it, going back a decade and more the list of categories was far smaller than it is today.
Why? It could be fusion. Where two types of music are fused to create a new one. It could be pure invention. It could be sounds in nature that we suddenly “discover”.
The audible spectrum for most people may not reach the highest frequencies that a good pair of speakers can handle but the range is there for an almost infinite combination of frequencies. Then there’s timing. Let’s just say that the potential of new sounds is still there despite the proliferation of different types of music.
Maybe my answer should centre around what’s on my phone. I’m predictable. It’s rock.