Surely the point is that because the world and the transmission of music and songs have changed then the terms need reappraisal.

100 years ago I don't imagine many folk singers bought a book of traditional tunes in Waterstones. they might not have the access to variants and research which a singer can have today. Also, the wider access to material and info by an audience erodes the idea of oral transmission being the main form of transmission.

Also, might we argue that any song written today might be considered for electronic media...