I've been playing folk music publicly for 40 years (not wishing to pull rank, you understand) and for several years before that at home or with friends. For all of that time I've been listening to people making authoritative statements about how English folk songs should be sung , and it always prompts the same two questions: who says so? and on what authority? Folk songs are what people sing, regardless of their provenance. I am of the belief that there is no definable difference between 'popular' and 'folk', as has been touched on in other posts; any definition for one applies equally to the other. These songs are not 'folk' because of how you sing them, but because you do. Some people like to tell us that we should be singing English songs as the shepherds, ploughboys and carters' lads sang them in the back rooms of country inns in the years before the Industrial Revolution. I would make two contentions about that. Firstly, they weren't following any rules about how to sing folk songs, because there weren't any rules. Nobody had told them they were singing folk songs; they were just singing popular songs. Secondly, If you deliberately, and as a metter of policy, sing the songs in the way that you suppose it was done then - not that any of us can remember that far back - then what you are doing is not 'folk' or 'traditional'; it's period music. Nowt wrong with that; I have been involved - on and off - with period music for about 35 years; playing music of an era on instruments of that era and in the way - to the best of our knowledge - it was played then. The pretence is that it's the 13thC or 16thC or whatever, and not that it's folk music.
I have heard people referring to 'the purity of the melody', as though a folk song melody is somehow more pure than any other, and is free from harmonic taint. It isn't. There are inherent harmonies. Some of us can hear them, and some, I suppose, can't. And not only that, but what one person hears may not be the same as what another hears. I have no problem with unaccompanied singinsg or playing - I have done plenty of it myself. But when I accompany a song, whether it be a complex - almost baroque - confection or simply melody/drone, or melody with a few bare fifths or octaves thrown in here and there, it's expressing the way that that song sounds in my head. WAV might not like to listen to it; that's up to him. He has made the comment in one or two posts that what he's learned so far is to play melody. Lots of us have been at it a lot longer; maybe in time he'll find himself doing more. but it won't make the music any less - or any more - valid as folk music.
John Kelly.