With a sigh
You turn away
With a deepening heart
No more words to say
You will find
That the world has changed
Forever
And the trees are now
Turning from green to gold
And the sun is now fading
I wish I could hold you
closer
EDIT:
Is it worrying that I just knew that off the top of my head?
EDIT 2:
If you were wondering, it's sung by Liv Tyler who plays Arwen. It's called Arwen's Song. You can also find it on the Return of the King Complete Recordings disc three track 11 "The Houses of Healing"