Here is a video describing how my VCF works. I forgot to mention the resonance control R17, but that's pretty much self-explanatory. I had it set to max for this demo to emphasize the filter operation. Here is the updated link to the filter schematic with the R27 correction:
https://drive.google.com/open?id=1Ac_viuOEBRzPwSZE1TOIzKb9LMa974HO
