however a good traditional singer like Phil Tanner who learned his songs and repertoire orally is worth recording,but not if he sings Humpty Dumpty.

I am not sure you know how and where Phil Tanner learnt his songs, Dick. Do tell.

But a problem with the early collectors is they made value judgments about what people sang, Instead of recording everything. Whose value judgments would you use? Apart from yours of course............