I'm in the process of digitising our vinyl collection and I came across this as part of the notes to a 'Folk Legacy album - it was written by a much-missed contributor to this forum, Sandy Paton.
I believe that it is relevant to this discussion as it touches on the effect of copyright on tradition song – a part of this argument yet to be responded to by those who claim that pop songs can become traditional.
Sandy's track-record in making available traditional recordings through his magnificent Folk Legacy label gives him a voice on matters such as this, as far as I'm concerned.

Many, many thanks for your thoughtful comments Vic - will respond to your PM either when things get quieter or when I get my head around multi-tasking!!
Jim Carroll   

13   Rich Girl, Poor Girl
This is related to a Negro song of variations on the same title ("Brown Girl, Black Girl", "White Girl, Brown Girl, My Girl", etc.).
Editor's Note: The vast number of bawdy verses generally found with this song would indicate that it has led quite a colorful life through its years of oral transmission. The structure of the song, in both its Negro and white versions, certainly lends itself to individual invention. Scholars studying the processes of oral transmission have found their work vastly complicated by the effect of the stall ballad or broadside, the songster, and the early recordings of country music on oral tradition. It has been observed that only in the case of blatantly bawdy material can the folklorist be sure that his collectanea is free of such influences. When Hank Ferguson originally recorded this song for Bruce Jackson, he had no way of knowing that it might, eventually, be used in an album produced for sale to the general public. At that time, he freely sang those verses which clearly establish that he could have learned the song only from oral sources. At our own recording ses¬sion, he chose to omit those verses. This note is inserted here for a particular reason: in recent years,   several copy¬rights have been filed on this song, or, rather, on "arrange¬ments" of this song, which brings up an important point — namely,   the difficulty in assessing the validity of copy¬rights now being filed on traditional or semi-traditional material.   This difficulty is becoming increasingly obvious to those who are working in the field of folksong and is causing a great deal of discussion among folklorists, both in America and in Great Britain, who, almost unanimously, deplore the attempts of individuals to possess, privately, portions of that traditional heritage which properly, it would seem,   should remain the property of all the people. I realize that this observation is not especially appropriate in this particular instance,   "Rich Girl,   Poor Girl1* being an unimportant song by comparison.    But the unfortunate fact re¬mains that a number of professional performers and songwriters are currently filing copyrights by the score on songs which have been in oral tradition for years — indeed, in many cases for centuries. We, of Folk-Legacy Records, Inc., share the growing concern of the academic folklorists in this regard and look forward, with them, to a prompt and thorough examination and legal resolution of the problem.
S.P.