Answer:
Each morning I appear to lie at your feet, all day I follow no matter how fast you run. Yet I nearly perish in the midday sun.
What instrument can make any sound and be heart, but not touched or seen?
Runs smoother than any rhyme, loves to fall but cannot climb!
I am the heart that does not beat. If cut, I bleed without blood. I can fly, but have no wings. I can float, but have no fins. I can sing, but have no mouth.
I am mother and father, but never birth or nurse. I'm rarely still, but I never wander.
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.