Fortunato,
I had a similar moment of triumph when my son and his friend were "rapping" Leaving On A Jet Plane and I gave them the next line. Sheer Horror when they found out it was a hit in the 60s. Pure disgust when I proved it with a reel to reel recording. My victory was short lived. They proceeded to raid my tape collection and plagiarize bits and pieces to create their own raps.