Oh oh oh my goodness, this one is magical indeed. The way piano music touches my soul, I'm likely going to learn how to play the piano.
Rising and falling of beats resembles our life which sometimes becomes calm and sometimes noisy but it keeps going.
And as you named it "Rain", what if somehow natural rain sound is added in the background. "A guy, all alone, deeply involved in playing the Piano while it's raining outside".
Simply Amazing. :)