It's one of those I've heard, but never really listened to or connected it to Christmas.
If you don't believe me, try the lyric video.
We are unpacking Isaiah's prophecy of a coming King in 9:6-7 in our Advent sermon series, so even though it surprised me a bit, this song was very fitting. Jesus embodied each of Isaiah's royal titles in a unique way and he certainly continues to embody the king who reigns and will reign forevermore.