I've gotten a long ways with all of your help, and just added more stuff to my uploaded C2 example, and I'm starting to get more familiar with Construct 2, and like it a lot more then C3 now (mostly).
Now, I have one last thing to do to get it to work.
I've seen blackhornet's Midi Plugin and indeed downloaded it, and it seems like it would be nice if it was updated a little bit later then 2014, after all, browsers didn't support MIDI back then. Last, but not least, I'm looking for a way to do what he did here, with the drag and drop a MIDI file, but (if possible) with a newer addon.
Sorry for posting again, but I really am curious, and spent many hours on this. If anyone knows of a free plugin or something that can help me achieve this without much trouble.
Thanks again!