For you Litterbox MML Editors (NDKJR3X3, Just in case), I'v started something you all will definitely recognize, it's not finished, but I'll let you listen to it anyway, since I've stopped to rest at the right time. Key for it: 433PB4FD.
All credits go to their owners. :P
So I recently re-typed in the key for Litterbox, an easier way to edit and make MML's without typing letter by letter (NDKJR3X3), but there's a syntax error around the beginning, someone tell me why and what's preventing it from working?
You can also give some keys for MML editors, just make sure it's Synthesia-like. (I'm only use to those.)