I was looking through my .minecraft folder and stumbled upon these sound files in the newsound folder (.minecraft/resources/newsound). In the steps folder, there are 4 sound clips for stepping on snow, meaning seasons are coming soon? Also in the random folder there's breathe and fizz which I have no clue what they are for.
The breath sound might be for emerging from water the fizz might be some kind of burning.
Theres even cave chimes, waterfall, ocean and birds singing sounds. And a whole bunch of other unused sounds!
Awesome!
But, the chimes that were spoken of, I did not see.
Also I think the fizz is when you're on fire and you jump into water/ lava touches water.