Didnt I help you with this?

The change of backgrounds goes very well with the beat but you clearly knew what you were doing. Since the paper isn't exactly in the center most of the time , it gives the viewer the opportunity to admire the background well so that was a pretty good choice. However, even though the paper slides smoothly across the screen I'm not sure what to think of it. I'm not sure if it is a distraction or a way to keep the viewers attention by not being repetitive.

When it comes to the animation, it is pretty neat actually. Sure it is pretty random and I doubt it follows a story or have any deeper meaning but that doesn't make it bad. In fact it can be quite fun seeing this sort of animation because it is almost impossible to predict what is going to happen next. I was surely not expecting the key to act as a light switch at all! I wouldn't change much about your creation but the score could have been higher if it was colored as animation without color can often look unfinished.