Fair, the synth especially I imagine. Didn't have time to implement the melody.
Though with how the game works, it's possible to change the loop over the game as it gets stale.
I'll be honest, I didn't beat the piano puzzle, even after help I couldn't process what pieces to do in order. But I do love the atmosphere and the hints are good, it's just that there isn't any clear way to tell what you're missing.
(I am also biased towards this because my original plan has a bit of this vibe before I realised I overscoped and started over)