Having found 2 open source tools that can convert any audio file to midi, I'm still interested if there are others (for comparison).
I've tried WaoN and Audio_to_midi_melodia.
But not all samples produce desirable output.
WaoN seems to work better overall, and tweaking the parameters (as well as using higher sampling rates as input) aids in getting more accurate results.
Any tips for other OSS tools or libraries that achieve something similar are greatly appreciated.