I took a course in Folk Music 101 years ago and was told by the learned professor that all the clues point to Barbara's poisoning Willie and then herself. He slighted her in a bar. She was humiliated and furious. And his last words are "Be kind to Barbara Allan" in other words a warning, "Stay on her good side." It made no sense to me - why then did the rose and the briar grow together in true love? Then again, why would two healthy young people suddenly take to their beds and die?I needed at least a C to pass the course so I fed it back to him on the final. The professor BTW did not know that "Follow The Drinking Gourd" was used by slaves to plan an escape. Don't think Folk Music was his specialty.