I didn’t catch this until I saw some screen captures, but the music piece in the background here is Beethoven’s Fur Elise.

Figure 1.0: Quite a bit of attention to detail.
I was surprised that they went through the trouble of putting in an actual score, although I guess with the shift to digital rendering of anime, this probably wasn’t too hard.
One thing I’d like to see in this anime is more piano pieces – since they seem to portray Haruka as more or less a virtuoso, I thought we’d get to hear more classical music.
Edit: The scene is from episode 3, around 27 seconds in.