If you want the music thing done, you take the help.. not push it on him to do it! It's not like he can come over and do it for you. I'm sure it's not hard anyway.
More to the point, I don't see why.. it's only going to be for your benifit, you may as well stick on a youtube video with the soundtrack going or something. (if you were editing a video to show off this world, then you can just lay over the music there and then.)
Oh, one last thing.. I take it you're making up your own Zelda World/Map, instead of say recreating one from an existing game.
In said case, I point you to this video.
http://www.youtube.com/watch?v=IZ2BcvowYl8
Eitherway, have fun with it. I've been wanting to build big things like that. Towns, cities, dungeons. I have a decent start on it.. it's just getting myself to go do it!