Hey there, I have some questions about the music!
Depending on what exactly you need, I'm feeling a bit like maybe I can help? I'm pretty nervous about offering it, since I don't know if I'll be able to do what you want done.
I've been working on my own FF1 hack, completely replacing all the music with my original songs. I've made a few videos here-- https://www.youtube.com/channel/UCQniGW1okFe8K_uBvh4kf2A
(scroll to the right to see the first one, which has a bunch of different ones in one longer video!) So I'm pretty familiar with things so far. I've learned how to edit a few of the "instruments", added another octave for deeper bass notes, changed the note lengths to allow shorter and longer notes... and even wrote two different forms of looping that save a ton of space and allow for more complicated songs. (Though one of them is weird and bugged and might not be viable after all.)
While Final Fantasy music is the reason I learned to write songs, and the reason I began to like music in general, I feel that a few of FF1's songs aren't really that great. And are, in fact, supremely annoying. But there are a few absolute treasures as well. I'd be nervous about changing much about things like the Undersea Palace music, or the Temple of Chaos music... But the reason I've done so much work with my hack's music is because I feel the cave music (Marsh Cave, I think Earth Cave too?) is just SO horrible. I had to write a song to replace it!
So, er, my questions would be, which songs do you feel should be replaced, which ones should be kept? I could see about writing a new song, or adapting other FF songs. Many of the songs I've done so far, I actually wrote for 5 or more instruments, and stripping them down into 3 single-note channels has been painful, but a good learning experience.
I would also love the chance to work with Disch's music engine! Actually, if you have someone else for music already, I'm wondering if you (and him!) would just be willing to share that alone, so I can see about using it in my own project... XD I'm very curious to see what he's done with it.
Oof. Actually, I'm not sure I can manage to help after all. I found the music engine Disch wrote in another thread, and its... whew, its a lot! So far as coding it goes, I think I'd be slow and useless... :(