Great idea! That would be a good break to change the tone of the instrument as well and perhaps apply a more complex and capable control setup like the one that juzek mentioned in the comments here.
That's nice to hear that it reminded you of the educational games - your game reminded me of my time I got to spend learning the basics of an old apple IIe when I was young (not a GUI system like the one in your game but still a similar experience).
Were you able to figure out either or both of the melodies in this game (or maybe get them by chance)? I do plan to do a longer version of this game with day and night as well as multiple seasons with different tunes, but after the feedback I've received here I am considering making it a longer and more drawn out experience. That will give ample time to ease the player in as well as get good use out of the mechanics.
Thank you for your engagement with the game and the feedback; much appreciated :)