I had heard about this some number of years ago but had never checked it out - until now. It's pretty amazing! You can read about it
here. In the meantime, check out the vid.
I almost wish a were a mathematician, because I can't help but wonder if there's some sort of mathematical phenomenon going on about human perceptions of time, or attention spans (e.g., people will want to pay attention to a scene/song for a certain amount of time before wanting to shift to someone else, and both the producers of The Wizard of Oz and Pink Floyd unconsciously were aware of that). Or something else.