A Spiritual is a African-American song with a religious text. Traditionally monophonic and a capella, these songs are antecedents of the blues. They began on Southern slaveplantations as work songs[?], sometimes with hidden messages of rebellion and escape from the slaves' owners.
... interview conducted ten years since Barsamian first interviewed Chomsky)
Rollback: The Return of Predatory Capitalism
History and Memory
The Federal Reserve Board
...