Don, I think we agree on the same thing, but we are just using terms in different ways.

My interpretation of "popular" implies that the song is popular among a wide range of people. Many of the traditional songs that we know today were not well known outside of a families "collection" or perhaps a certain geographic area. No one kept these songs in books but learned them by memory and shared them from generation to generation because the songs were good or related to their own experience.

A song that may have had relevance to a family living in Novia Scotia would not necessarily have the same significance to a family in the Ozarks - even if there were a chance that the same song was shared in such diverse locations. The folk tradition would have shaped a "good" song to fit the time and place.

During the folk revival and beyond, many people were exposed to traditional music either through recordings or the books put together by collectors such as John & Alan Lomax, Carl Sandberg, etc. Today, I think that there are fewer instances of songs being kept local because of technology.