Answer:
Thirty men and ladies two, gathered for a festive do; Dressed quite formal, black and white; soon movement turned to nasty fight.
I pass before the sun, but make no shadow.
You need a key to receive an answer from me. The answer you'll find is straight from your mind. What is it?
What is up that’s also down? What’s a smile and a frown?
A reaction to being spooked that takes its name from waterfowl
It's what light turns into in the night