Would be nice to have a link to the music itself, both recording and sheet music.

This is the E minor prelude - I happened to recognize it by key but not by number.

See e.g. the Wikipedia article (https://en.wikipedia.org/wiki/Prelude,_Op._28,_No._4_(Chopin...) which has a recording embedded, although there are surely better ones.

Sheet music from IMSLP: https://s9.imslp.org/files/imglnks/usimg/3/3c/IMSLP319636-PM...

Thank you! That is a crucial omission.

I avoided including the MIDI/Score files in the repo to avoid licensing issues, but I have updated the analysis document immediately with the Wikipedia and IMSLP links.

The ideal experience (as shown in the README gif) is actually running the visualizer alongside a score editor like MuseScore via MIDI port sniffing, so you can see the geometric cursor sync with the sheet music cursor. But for reading the text, the recording is essential context. Thanks for the links.