Loops

Loops are sound files not yet used in the game, and are possibly to be used for when the player is in a specific type of location (caves, woods, sea and beside a waterfall)

They can be found in /.minecraft/resources/sound/loops/, and can be converted to reveal loops of birds chirping, cave chimes and waterfall noises. Early Minecraft sound mockup by C418 using these loops.

Converted
Converted files can be downloaded by clicking on the following links:

Birds Screaming Loop

Cave Chimes

Ocean

Waterfall bottideedoo