I'm sorry, Undertale is probably not even relevant anymore. But this has to be one of my favorite themes from the game and I've wanted to remix this correctly for a long time. I have tried in the past, but this is definitly the one I will keep. And yes, for those who want to know, I did use a MIDI. I just extended it a wee bit.
(Fun Fact: Before I knew how to use a MIDI and before I knew they even existed, I would look up Synthesia videos on YouTube. I copied down each individual note, going from Audiotool to YouTube back and forth.)