When Herod the king had heard these things,
he was troubled, and all Jerusalem with him.
So many of my favorite Christmas songs are in the minor key -- I realize that looking at these songs standing all together.
I don't formally follow the Advent schedule but there is some deep psychological wisdom to that progression. To jump from everyday life into jubilation is a recipe for the kind of overindulgent excess that leaves too many of us feeling tinselly and tawdry and bloated with emptiness come Christmas morn. I need the inner pilgrimage through these songs of yearning and desire, through mourning and awe so that I can come through to the light of that morning as from a cave.
The point of Christmas is not simply that a dear little Babe was born with beautiful golden-voiced angels strumming their harps and singing about peace. It's that the dear little Babe and the golden angels happened in a world where soldiers slaughter babies and hatred rings so loud you cannot hear your heart cry out in anger and grief. There would be no News! News! (which is what Nowell means) if peace were already on the earth and good will to men was happening already.
The point is that there is nothing much we can do against Herod the king and his raging. We keep trying, we keep failing. War and riot keep breaking out despite all our years of practice. This rage and hate is the very reason why the Baby came, to teach us the better way by walking through it Himself, to show us how it can be done, to fix what we have broken and keep breaking.