Cool. My one concern with this is that it has no horizontally scannable note/chord mode. It’s super common for humans to read a sequence of notes left to right, or write it that way, but it’s also just more efficient in terms of scanning / reading.

Can I suggest a guarded mode that specifies how far apart each given note/chord is by the count, e.g.

  #1.0:verse1 
  Am - C - G - E - F F F F
  #

  #0.25:melody1
  C4 - C4 - C4 D4 C4 - D4 - D4 - D4 E4 D4 -
  #

I considered it but decided against it in the first version, because specifying note durations is too tricky. It was more important to get the .mid -> MTXT conversion and live-performance recording working, where notes usually have irregular note lengths. Representations like "C4 0.333 D4 0.333 E4 0.25" feel too hard to read.