I missed the whole "Window of Joy" thing - please fill me in

[Rabrrrrrr]

First off, what is a "Window of Joy" and how did it start and by whom? Secondly, please define a metope.

[hfojvt]

1. it came upon a midnight clear

"Joy to the world
the Lord is come
let Earth receive her king
let every heart prepare him room
and heaven and nature sing
and heaven and nature sing ..."

Of course, I could be wrong about that
but I thought it had something to do with a son and a god.
or was that a dog?

[sundog]

2. a controversial subversive plot to make people smile

origins rooted in witchcraft & voodoo

[FuzzySlippers]

3. The Window of Joy looked out at a scene like this: