Wow, this is a super sweet idea.
I like how you have to try to avoid the different notes in order to get the note next on the scale. It is definitely a unique idea that I haven't seen so far. Though I have to say that resetting the whole progress was a bit frustrating, I was so close to the end multiple times and then had to completely start from the beginning. It wasn't a big deal, but I thought I would mention it.
One thing that also might have been nice is a bit of relaxing, quiet background music, because if you are looking for a specific note and it doesn't spawn in a while, it's pretty much complete silence.
Besides that, the drawings are absolutely gorgeous, and seeing the different stages from start to finish is super cool. I really love how you interpreted the theme. Really cute, small game. Good job!