marje said,[its very limiting to dismiss something because it hasnt got the right label on it].
I agree,However I believe[and if I am wrong Im sure I will be corrected] collectors like Sharp, did do just this, by restricting their collections to specific areas[geographically and socially].
COLLECTORS ARE FACED WITH A DILEMMA ,Do they collect everything from a singer,whether its a composed peice or music hall song,or a song learned by FROM THE revival process.
Do they not collect from foOtball grounds,Because the performance might be inferior.
If they dont they could be making a decision based on performance.
as far as I know Sharp never collected music hall songs or industrial folk songs,He made a decisionas regards categorisation.