Answer:
You use me from your head to your toes. The more I work, the thinner I grow. What am I?
I mirror your actions.
I am black and white. I have strings I have keys. I make sound without my lips. I make dough with no flour
I am the kind of nut that is empty at the center and has no shell.
I have a gown but I'm not a priest; I have a crown but I'm not a king.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.