Since it is back I will ask what I was going to ask just as it paused.

Is there a term for the subset of 'what the folk sang' (and of what falls within the 1954 definition and what as revived in the post 1950 folk clubs) that has been the centre of discussion in this thread?

Almost all the songs mentioned here were sung (and revived) by solo singers. No-one seems inclined to discuss wassail songs, work songs, local carols, drinking songs etc.

They tend not to have the catchy tunes and easy-to-join-in-with rhythms of the music hall, pleasure garden or stage tunes that are known to be such. As discussed above scanning the words into the tune can be tricky.

There melodies often feature modes other than the major and minor of 'art music' and often use gapped scales.

From the descriptions of and by many collectors there seems to have been a collection bias towards these features and a tendency of source singers to offer them.

If, in a parallel with Lloyd's eastern European truck driver, a carter had heard the lads of the town singing something from the pleasure garden then gone home and wrote a little song to a similar tune would we identify it as a 'folk song'? Or would it be regarded as just another example of popular song?

Is there a name for this 'sub-genre'. It is almost as if the collectors and revivalists had selected for 'unpopular song'.