Actually, and perhaps more correctly, I should say that his question is about a particular reproduction of the Ultima 5 soundtrack, which he was unable to reproduce (if I read him right).
Well. I’ve been searching for more info on this for a while now. Last night just before my Apple IIe blew up I think I’ve worked it out. (Now I have a broken Apple IIe
The guy that posted the youtube video wit the music says on his website that he mixed it in after.
I have an Apple IIe with a midi interface card and using a Roland Sound Canvas you can access one channel only. Ultima V lets you configure this. But you are limited to one channel so to reproduce the music he has on his youtube is impossible. If anyone else can confirm this let me know.
This sort of question is beyond me, though it is an interesting query about some very classic pieces of computer audio hardware. If anyone can supply an answer, please do!