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.
... Line, District Line or Northern City Line (Great Northern & City Railway) remain open as mainline stations:
Great Missenden tube station[?]
Wendover tube ...