In all of history, this had to be one of the most unconventional ways to try to defend a country under siege. Who ever heard of an army being led by a group of singers and musicians? But sing and play they did! Here is the true account from the Bible's book of 2 Chronicles, chapter 20.
Word was rushed to Jehoshaphat, the king of Judah, announcing the swift approach of a vast army from Ammon, Moab, and Seir, three kingdoms that had formed an alliance against Judah.