Question: vmpk how to connect midi keyboard?
Answer: Install the "patchage" and "fluid-soundfont-gm" packages.
Open Jack Control.
Review JACK configuration to ensure it is attached to your preferred audio interface.
Start JACK (the big play button)
Open Patchage.
Open vmpk.
Open Qsynth.
In patchage, connect vmpk MIDI out to Qsynth MIDI in.