Answer:
Half-way up the hill, I see you at last, lying beneath me with your sounds and sights. A city in the twilight, dim and vast, with smoking roofs, soft bells, and gleaming lights.
I bind it and it walks. I loose it and it stops.
What comes once in a minute, twice in a moment, but never in a thousand years?
What kind of room has no windows or doors?
It's in your hand though you can not feel it. Only you and time can reveal it.
I can only be played on a windy day