No big downside; it will just take some refactoring of the code, and I originally hesitated to have three letters in an input box since two letters (e.g. an A#) already fills up a lot of space.

> Perhaps you could also give the player an easy way to change the octave of a note after inputting the note

I really like this idea, and will have to think about maybe putting a superscript next to each input tile (or something) that lets you toggle up or down to change the octave. Will have to think about the design!