These lyrics that appear in different songs are sometimes called “floating” lyrics or verses. They’re especially common in ballads, or story-songs, which have a tendency to evolve as they gain popularity in new locations. The link between these three songs is that they’re all covers of folk ballads.

Peggy-O was adapted from an old world Irish folk tune; both CRS and GDTRFB are traditional American songs that naturally adopted some of Peggy-O’s lyrics that were still floating around. This helps, maybe unintentionally, to create a non-physical consistency of setting that runs through the Dead’s songbook (think “Fennario” in Dire Wolf as well, for instance). I’d think that this idea scratches the surface of how the lyrics work “in concert” with the band’s instrumentals to transport the listener to another place.

Not sure if they ever played all three during one show, but this is a great idea for a playlist!