Seriously, ch 4 gave me feels I haven't had since I played Chrono Trigger and Chrono Cross a few years ago (for my first time) with that soundtrack. It's phenomenal.
The music puzzles just ended up with me dicking around on the piano too.

You can tell he's spent most of the past few years doing soundtracks for people.
Shame he kinda went light with the gameplay, though it got better in ch 4...