Answer:
Come up and let us go. Go down and here we stay.
Where do you go in through one hole and come out through two holes at the same time?
What has four legs during the day; and six or eight during the night?
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.
Of these things - I have two. One for me - and one for you. And when you ask about the price, I simply smile and nod twice.
Dark, feathery, and popular in Baltimore and fantasy books.