. >> reporter: films of slavery are rare, and last year jane ge un -- "jiang go unchained" and it looks for the relationships with god. >> he is someone who is active and alive in his spirit, and in his soul, and he is in that completely sort of unbreakable. ♪ well he was a preacher called ♪ ♪ and my bible said so too ♪ i said roll johnny roll ♪ roll johnny roll ♪ my soul arrives in heaven lord ♪ ♪ hallelujah ♪ roll jordan roll >> when solomon burst into song at some point, because he could cling on to it was alive and hope, and because if he didn't, he would lose his mind. this tells you how important, of course, religion was into keeping the people sane. ♪ my soul arrives in heaven lord ♪ ♪ for jordan rolls >> and songs like "sweet chariot" teaches about the experience of slaves, a code. >> they come from a place of catharsis and healing, because they were looking of a story of the israelites that they had endured bondage and had been freed and translating the stories for themselves, says that god hears me, and god knows, and he understands my system of bondage and god understands my