There are only two times I've encountered an entirely black screen, with the music still playing and not actually frozen. First time was when I was aiming an arrow into the depths, and the camera did a nosedive INTO THE CHASM.
It was pitch black, but with sound and nothing frozen. I had to pull my camera back, or swivel the left joystick a bit (just do a 360) to readjust the camera.
The second time was when I finished a playthrough and there was supposed to be a cutscene in a room, but rather than putting me in the room, the room was floating in the center. It was also pitch black, until I rotated the room to the front side. It was very strange, but both "black screens" were fixed by adjusting the camera position.
I never experienced a black screen just by leaving the game on though. So I'm not sure if this is the same thing you're experiencing.