One of the most memorable things about Ultima IV for me was the music. I had the game for C64 and can still remember it fondly. Now I get 1-6 and find there's no music in 3, 4, or 5! I got XU4 for Ultima 4 and have better graphics and the music but still nothing for the other games. I know these are the PC ports and not the original Apple, Commodore, IBM, etc. but I thought there was music for them.

There's no music for the original DOS Ultima 5, but there is a patch to put music in. Here's the link: http://exodus.voyd.net/download.html
The site also has a patch for Ultima 3 which adds music and graphical improvments.

Or just use Pix's Ultima Patcher. It has patches for all the ultima games released on GOG (including patches I've not been able to find in other places), and is quite easy to use.

And as the above guy said, the DOS versions of III, IV, and V don't have music normally cause of shitty PC speakers back then.