When Walter Pardon's name was mentioned previously I looked him up on Wikipedia. It says there he sang music hall songs and gives the title 'Old Brown's Daughter as an example. It also says that Pardon learned many songs from an uncle who learned them from Pardon's grandfather. It says that Pardon believed that his grandfather got his songs from broadsheets.

You end up not knowing what to believe.

Did somebody say he used his melodeon to work out tunes: this suggests that he was learning new ones from a non-oral source?

I think it would be interesting to carry out Steve's suggestion. It would be good if the songs chosen were ones on Spotify, so that those of us who don't have the CDs can listen to them. Could we have a list?