Firstly what is the overworld? The Zelda 1 instruction booklet says the overworld is:
Forests, Lakes, Mountains. Link must fight many enemies in a beautiful and natural world. We can be pretty certain however, that some good-natured people living in these places will help him out and be his allies in his fight againt evil.
Since people live in towns usually that makes all forests, mountains, lake areas and towns part of the overworld according to Nintendo's definition of the overworld. I will select my favourite overworld music pieces based on Nintendo's definition of the overworld.
My top 5 Overworld themes.
5. Clock Town (Day 1) - Majoras Mask
A great theme and really gave the town character.
4. Gerudo Valley - Ocarina of Time
Obvious choice here as this is the only decent piece of the music in the game that original and not a remake or rip off from the ALTTP music. Koji Kondo is quite the genius for coming up with this piece.
3. Forest (Light side) - A Link To The Past
Not a long piece but what is there is mysterious and makes you want to explore and see what's luring deep within.
2. Ocean - Wind Waker
The only good piece of music from an otherwise musically terrible game. This piece screams out Epic Sailing Adventure. Without this piece of music Wind Waker as a game would be much harder to tolerate and play.
1. Dark World - A Link To The Past
A unique take on a dark world musically. It's not pure evil. There is shades humanity hidden within. That's why this piece is so amazing.