Which Christmas Song/Carol really means Christmas is happening?

[tulpe]

For me, it is always either Oh Night Divine or Once In Royal David's City. Both make me very tearful and hopeful for a good christmas

Which song really kicks the whole thing off for you?

Good King Wenceslas. I have no idea why, I just like it.

The last verse of 'O Come All Ye Faithful' - we sing it a the very beginning of Midnight Mass, as baby Jesus is put into the crib, and never before.

'Yea Lord we greet thee
Born this happy morning'

The start of Christmas Day

on a lower cultural note Fairytale of New York