Answer:
I have four wings but cannot fly. I never laugh and never cry. On the same spot always found, toiling away with little sound.
What has roots as nobody sees, is taller than trees. Up, up it goes, and yet never grows?
When there is fire in me then I am still cold. When I own your true love’s face then you will not see me. To all things I give no more than I am given. In time I may have all things, and yet I can keep nothing.
My voice is tender, my waist is slender and I'm often invited to play. Yet wherever I go, I must take my bow or else I have nothing to say.
Talks like this, a green wise man does. Guess my clue, you will.
What is always coming but never arrives?