ScroogeD

This is due to the converter using ((startTimeOfFirstConvertedNote - startTimeOfLastConvertedNote) / FullDuration) to calculate the percentage, without taking into account the duration of the last note.

Chords are sometimes arpeggiated after conversion despite playing at the same time when listening to the MIDI file

1

The timings of some MIDI instruments are saved in a weird way that causes them to not start at the same time in the MIDI data, but still *sound* like...

ToneJs/Midi assigns each track a channel while parsing, instead of giving each note a channel. Due to this, Type 0 MIDI files (where all notes are in a single track)...