What would a wedding be without music?
Anyone who knows Jack knows that his favorite movie series is the Lord of The Rings. He's made Ava watch the extended movies with him countless times and can quote every line of every movie.
The "Concerning Hobbits" song was playing as they were getting ready and as they were sayiong their vows.
The "eye of Sauron" song did pop up once or twice which gave them a good laugh, but then was quickly skipped on to something more peaceful.