Neil, it is an example of floating stanzas. Paul Oliver notes in 'Screening the Blues' that 'at some indeterminate time' in the 19th century, the 'run nigger run' and 'some tell me that a nigger won't steal' etc stanzas became associated with the song generally known as 'You Shall Be Free'. Odum collected a version in the early 20th century and published it in 1911. He stated that it 'was originally adapted from a religious song, "Mourner, You Shall Be Free"'. The song was widespread. Oliver notes its collection under titles such as 'There was an old nigger, his name was Dr Peck', 'Ain't no use of my working so hard', 'Ole Marse John, Pore Mournah', 'Po' Mona' etc. The latter had the chorus:
Po' Mona you shall be free
Gooba-looba, Nigger, you shall be free
Keep a-shoutin', Nigger, you shall be free
When the good Lawd sets you free
Sigmund Spaeth published a version in 'Read 'Em and Weep' under the title 'Mona (You Shall Be Free) and commented that it 'represents the more sophisticated development of Negro folk music, with only a suggestion of the spiritual in the background'.
Uncle Dave Macon recorded a version in 1926 under the title of 'Shout Monah, You Shall Be Free'. Bob Hyland in his notes to 'Dixie Dewdrop' Vetco LP 101 noted that the song was of 'spiritual and minstrel popularity' and 'has had all sorts of lyrics and titles'. It was later recorded on Columbia by Bill and Belle Reed as 'You Shall Be Free', on Victor by the Carolina Tar Heels as 'When the Good Lord Sets You Free' and, as a pop song, under the title 'Oh Monah'. Uncle Dave later sang versions on radio verses that differed greatly from his 1927 recording.