For some reason, I just like Advent. I'm also not terribly fond of most Advent music. It is often slow and mournful: think of "O Come, O Come, Immanuel." No doubt it inspired a quick pulse when it first came out, but we have since moved on to a little peppier music. Besides, despite the fact that we may be in trouble now, the possibility of what the coming Messiah will bring should inspire hope and joy!
This song is based on that joy and expressions of what will come. Like a lot of good folk music, it has a gimmick: the basic lines get longer and longer, faster and faster, higher and higher. If you're singing this right, you should be out of breath at the end of the song! And shouldn't Advent be a breathless experience?
And to the critique that one line remains unrhymed and the poem unresolved.... That's right. And that's Advent. It isn't resolved yet.
To musicians everywhere: I apologize if the score is unplayable. Rather than calculate out the sharps and flats for each key, I let my score program transpose up a half step each verse, and it put out a lot of double sharps. I'm not sure that any living banjo players can actually play this piece as written, but it should be performed more along the lines of someone improvising to the chords. Good luck!