The reason why it's missing velocity is because the MIDI.js implementation used is a simple sample player - it converts Soundfonts into a subset format. Basic f

The reason why it's missing velocity is because the MIDI.js implementation used is a simple sample player - it converts Soundfonts into a subset format. Basic features like pitch bends and vibrato are not possible from this format. (With the newest revisions of Web Audio API it should now be possible to make a performant, fully-featured Soundfont implementation.)