Cool! I'm doing the same sort of thing in .NET Core, C#. I'm also having trouble coming up with how to implement sound, since I would love to have sfx and music. I've worked with Midi before and it would be in my best interests to actually use trackers to build it, but I'm not sure how to read and process it back into audio other than bounce to wav (.ogg, or whatever codec...) And even then, I'm not sure how to play it back...
In any case, good luck! I look forward to playing entries, and if you find a solution, let me know :)