Advent Hymns

I saw mentioned on a youtube that Christmas songs tend to make someone sad (I believe it was for Silent Night). As this Advent season went on, I noticed there is a slight melancholy tone to the songs. I thought about it a bit, and came to the conclusion that hymns, especially Advent, are the songs of those in exile. I would imagine exile tends to be a sad and yet expectant state of mind (not having been in exile on earth). Given the additional subject matter of God coming in the flesh to die for our sins, and I can see how some hymns are especially sad-sounding. I am not sure if anyone else noticed it, but it was an interesting observation over the Advent season.