If overworld music in zelda changed depending on what time of day it is, it could add some nice depth to the music. What I mean is add on to the overworld music as the day goes on.
Here's an example:
First, of course, the day start theme:
http://www.youtube.com/watch?v=3tRWZ...eature=channel
Then it opens up the ocean theme with this:
http://www.youtube.com/watch?v=vfuRY...eature=related
At around the half-day point, it gradually adds to the first one to make this (first strings, then low brass, and so on):
http://www.youtube.com/watch?v=JrexI...eature=related
Around the time the sun sets, it can gradually fade with a variation of some sort. I imagine it sounding something like how this song sounds around 3:30-4:20:
http://www.youtube.com/watch?v=-SovM_ExoVg
Eventually it fades into a night theme of sorts, maybe like you can barely hear the tuning of an orchestra or something like that.
Keep in mind that this is just an example. If they are to do this, I would expect an entirely new overworld theme.