OMG! I have the perfect song. You might not know it, but it's a beautiful song. It's called For Good, and it's from Wicked, the Broadway musical. It's so beautiful, so here's some lyrics:

"It well may be, that we will never meet again,
In this lifetime, so let me say before we part,
So much of me is made from what I've learned from you,
You'll be with me, like a handprint on my heart,
And now what ever way our stories end,
I know you have re-written mine, by being my friend.
Like a ship blown from it's mooring, by a wind off the sea,
Like a seed dropped by a skybird, in a distant wood,
Who can say if I've been change for the better?
Because I knew you, I have been changed For Good."