| Before the American Civil War, songs were used by slaves to covertly
communicate. Unlike holler songs, zipper songs involved the use of more than simple codes
to maintain secrecy.
Zipper songs were a form of lyrical steganography -- words were modified or new verses added to well-known
songs in order to convey a secret meaning. Wide-spread spiritual or traditional songs (Will the Circle Be
Unbroken, Amazing Grace or Steal Away to Jesus, for example) were often used.
Consider this modified first verse of Stairway to Heaven by Led Zeppelin:
There's a family who's sure all that glitters is gold
And they're building a stairway to heaven.
When you get there you'll know, by the rose on their post
With a word you can get what you came for.
Ooh, ooh, and they're building a stairway to heaven.
Hopefully, this verse is similar enough to the original to not arouse the suspicion of casual listeners while still conveying a message to those who know it's there.
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