Would love it if you could go into more detail about those two weeks. Had you already played around with tone.js beforehand? Did you have an idea or a draft written up for that initial lesson so you knew what was gonna be in it, and was it your initial vision to have a picture of each waveform accompanied by the sound, and buttons for each note in the scale? Did you have to change part of your design (even small details) when you discovered that it was hard to build something a certain way and that another way would be easier?