Neovim/Lilypond: MIDI Files in the Terminal and More

I recently wrote about using Lilypond with Neovim. My current composition has a mix of wind instruments and a MIDI keyboard controlling a Max/MSP patch. Crucially, the Max patch plays a variety of custom samples, sequencers, and other things that don't necessarily correspond to the pitch of the key being pressed. To accurately hear what I've written, I'm playing MIDI files over the IAC bus on macOS, sending the MIDI data into Max/MSP, where I have both the keyboard patch and another patch with virtual instruments for the winds. The workflow I described worked OK, but there were a few issues with MIDI in Audacity. I had chosen to play the MIDI file from Audacity since I could conveniently script it to reload the MIDI file whenever the file updated, and Audacity works with IAC. Audacity note tracks seem to internally convert MIDI to the Allegro format, and whether because of that or something else, I noticed that faster rhythms played back with some lag. I also wasn't able to place the…