Good Riddles

Question: You can rest on my pad without touching the keys.
I will sing all month long as long as you pay your fees.

What am I?

Question: A father's child. A mother's child. no one's son.

Who am I?

Question: An electric train is traveling south. Which way does the smoke go?

Question: A man drops an egg onto the cement. The egg doesn't break after falling 3 feet.

How could this be?

Question: Take my first and make it my last, now I happened in the past.

What am I?