@ Jack

I think that the Julia Bishop sections in Roud's book on Folk Song in England begin to problematise the way that 'modes' have been used to think about folk song. As I said before, these sections are 'tantalising' because for me they don't go into the amount of detail or depth that I felt ready for when I read and re=read them.

Creating harmonisations of 'modal' tunes is one thing Sharp does touch on in the piece we have been discussing. He criticises a European composer who treated a modal melody as a with 'modulations' and who introduced classical music type leading chords to get from one key (as perceived by the composer) to the other key (as perceived by the composer).

This is why I asked many posts back whether people could point me to an example of a Cecil Sharp harmonisation of a modal tune, to see for myself how he approached the problem.