Move the cursor and the note will move with you. Hold the "1" key for sharp and the "2" key for flat. Click to play the note. That's it. If you have any ideas of what to do with this thing, please tell me, or better yet, remix it! Phosphorus makes this project WAY better! Make sure to use turbo mode, because otherwise the ledger lines will go haywire. https://phosphorus.github.io/#256117974 (Hint: Try going in phosphorus and wildly moving the mouse and clicking.)
I did not want to make a treble and bass clef. The flat symbol was hard enough for me already. In the (not distant) future I would like to improve the interface by making the notes go a little lower than they do currently.