Twas Capercaillie's Karen Matheson singing in "Braveheart."

Listen closely for a stanza of "Sally Brown" in the A&E movie "The Crossing."

And did you know that when the Confederate submarine snuck up on that Yankee ship during the Civil War, the crew could hear the Yankees singing "Fiddler's Green," an "old Irish" ditty that somebody's mom used to croon to him years before? You can watch it happen in TNT's "The Hunley" (1999).