Answer:
I am the tool, for inspiring many. Buy me in the store, for not much more than a penny. Don't overuse me, or my usefulness will go.
Plow and hoe, reap and sow, What soon does every farmer grow?
A house of wood in a hidden place. Built without nails or glue. High above the earthen ground It holds pale gems of blue.
When the horse strokes the cat, the wood begins to sing.
Look into my face and I'm everybody. Scratch my back and I'm nobody.
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.