Most people know the lyrics to “Swing Low, Sweet Chariot.”

Swing low, sweet chariot
Coming for to carry me home
Swing low, sweet chariot
Coming for to carry me home
I looked over Jordan, and what did I see?
(Coming for to carry me home)
I saw a band of angels coming after me
(Coming for to carry me home)

Fewer people realize how songs like this, sung by many Africans enslaved in America in the 18th and 19th centuries — that we now call spirituals — had coded messages.

“One of the important functions enslaved Africans wanted this music to serve was to help them with their quest for freedom,” says University of Denver professor Arthur Jones. read more