Springsteen took melodic inspiration from the soldiers' marching cadence called "Freedom." (Often known as "Some Say Freedom is Free.")
"Adam had a cadence that they sang in boot camp, and [Kilik] recorded him singing it on his cell phone," director Jason Hall told Backsteets.com
. "Jon is friends with Bruce and played it for him. Bruce was like, 'Oh, that's cool. How'd the movie turn out?' 'Movie turned out great.' We played him the movie. Bruce loved it, watched it twice, and then said, 'Send me that recording, come back in a month, and bring that kid.' So Adam went up there with Jon and recorded the song with him."