Egad! You had to ask THIS one and open THAT can of worms!

What is it that makes a piece of folklore ‘urban’?

Nothing much. …

But, then, this is /r/AskHistorians so a bit more elaboration may be necessary.

The term “urban legend” marks a shift in the focus of the discipline of folklore studies more than it does any real transition in the nature of oral tradition. The original focus of scholars who dealt with what would be known as “folklore” (the term was coined in 1846) was the “old material.” Folklorists – notably the nineteenth-century Germans, Jacob and Wilhelm Grimm, were fascinated by the “old” stories that seemed to harken back to an ancient world.

The general perception was that the folktale (elaborate narratives told as fiction – the oral novels of the folk) were very old and changed very little over time. There was also a perception that the best place to gather this material, the place where the folktale had the most fidelity to the original ancient material, was a rural setting.

Western Europe in the nineteenth century was experiencing a transition that was shifting populations from the countryside to the growing cities. Early folklorists regarded themselves as conducting a “salvage” operation, collecting the old stories before they disappeared. While rural life seemed to change very little over the centuries, it was clear that times were changing, and whatever the old storytellers had in the repertoires might be gone in another generation or two. Folklore seemed to be evaporating before their eyes, gossamer dissolving under the withering morning sun.

Thus, the focus of folklorists for more than a century was rural and “old.” In the mid twentieth century the focus of folkloristics shifted. There was abhorrence over how nationalists/fascists had embraced their romanticized visions of old “traditional” culture of their “pure” ethnicities. There was also an emerging understanding that the hope for productive “salvage” folklore gathering was no longer realistic in most places.

At the same time, there was a growing understanding that everyone – not just people living in a rural setting – has folklore. If you’ll pardon the expression, “it’s all folklore.”

All of this inspired many post WWII folklorists to begin the process of considering non-rural, non-archaic forms of folklore. The term “urban” is unfortunate because it implies that modern stories are told only in cities, but not in rural setting. In truth, modern folklore does not respect such a boundary. That said, the term “urban” carried with it a powerful means to establish a shift from the older, rural focus of the salvage folklorists to the traditions in a modern setting.

The American folklorist Richard Dorson was one of the first to use the term “urban legend” – as early as 1968. In 1975, Alan Dundes and Carl R. Pagter published Word Hard and You Shall be Rewarded: Urban Folklore from the Paperwork Empire. Beginning in 1981, the folklorist Jan Harold Brunvand began publishing his extensive library of books of urban legends, and he has since become the go-to source for these stories.

It is noteworthy that the first folklorists focused largely (but not exclusively) on the folktale. There were also legends (generally briefer stories generally told to be believed) and ballads as well as other forms of oral traditions. In a modern setting, the folktale has tended with wither – although there are still elaborate jokes. The modern focus has been on legends.

The term “urban legend” suggests, consequently, several transitions that have occurred in modern folklore studies – as well as in the traditions themselves. From the point of view of the folklorists, the shift has been away from the rural and the historic to the contemporary; at the same time, the nature of the oral traditions themselves have shifted from diverse forms of narratives including the elaborate folktale usually collected in a rural setting to the legend, which can be collected from contemporaries in any setting. “Urban” consequently is shorthand for modern, and “legend” refers in some ways to a shift away from the old-fashioned folktale to the focus of many of the contemporary narratives.

See what trouble you caused. Shame on you!