Answer:
I am an instrument capable of making numerous sound but cannot be touched or seen.
I am full of holes but still hold water. What am I?
Without a bridle or a saddle across a thing I ride a-straddle. And those I ride by help of me though almost blind are made to see.
I have a head but never weeps. I have a bed but never sleeps. I can run but never walks. I have a bank but no money. What am I?
What can you catch but never throw?
No matter how little or how much you use me, you change me every month.