I really liked the originality and art for this game!
I'm not a musician, so it took me awhile to grasp the controls and figure out what note I needed to hit (I was playing on keyboard).
I was able to get one of the bird melodies, but that was through messing with controls and getting it by accident. When I saw the scene with the melody's notes and practiced with that I was able to figure out the melody and controls better in the next playthrough.
The conversation in the comments remind me of a video I watched from 8 Bit Music Theory (while trying to learn music theory) about how Koji Kondo wrote the LoZ: Ocarina of Time music with N64 system restrictions and the goal of gamifying music to be played with the c-pad and A and B buttons.
Having a tutorial showing each button and their corresponding note might help visual learners like me pick up the controls.