GUEST, JTT, I don't know the answer to your question.

But you said, I can think of some songs - like Follow the Drinking Gourd, for instance - that appear to be religious but are coded instructions to slaves for escape to freedom.

And I have to commment.

I don't think I have ever heard anyone suggest that Follow the Drinking Gourd is or was a religious song, and it doesn't strike me that way, even when trying to see how it could fit that mould.   To my way of thinking, and as I've always heard referred to, it was what might be called a "political" song, a "freedom" song.

Dave Oesterreich