Well I didn’t hear from Johnathon Coulton (JoCo) but I did hear from one of his minions, who said, “Hi Kat — Joco’s disfigured henchman, Scarface, here. Thanks for your message. All of Jonathan’s music is under creative Commons licensing, so as long as you’re not making money you can use his music in your art most any way you like. HOWEVER — the only songs excluded from this are the two portal songs, as those are owned by the video game company that commissioned them. If you want to be totally sure of your usage, you can email (message reducted by this poster), who might be able to help you more with this one. Best wishes — Scarface”
Even though I’ve already determined what I’m doing is covered by the law, I shall make contact to this portal contact and see what happens.