I once read a story where the author conflated Barbara Allen with The Brown Girl ("I am as brown as brown can be", in the DT here) as being the the same story told from two different points of view. In The Brown Girl, the young man initially scorns her because she is "too brown" ie, is tanned from doing manual labor, and therefore of a lower class than him. By the time he realizes his mistake, she wants nothing to do with him and scorns him on his death bed.

There are some who hypothesize that "Barb'ry" = Barbary, or a dark-complected woman; if Barbara Allen was a Romany, it adds a twist to the story. Martin Carthy talks a bit about this in the liner notes for the "Waterson:Carthy" album, Broken Ground.

It was an interesting theory, as the stories do mesh well. I like Frankie Armstrong's version of The Brown Girl, and my favorite version of Barbara Allen is the one sung by Caroline Paton, which she taught to KathWestra - "It was in and about the Martinmas time..." - although Art's cowboy version with its image of Barbara making "all the boys ride saddle sore" is a close second...