As Martin indicates, yet another complicating factor is the assumption that the tune is the same / works the same way for each verse, when consideration of the song in action shows so many subtle variations and possibilities, e.g. Susan-Marie's 'weary farmer' phrasing. One of the joys of working from the printed page can be the creation of such 'interpretation', and often the conscientious editor emphasises that the tune as shown is a sketch / outline / averaging out of verses. Whereas the recorded version can trap you in the moils of some other singer's personalised version. This of course is an argument for working from the printed text - the opposite of my above expressed opinion. On balance I think I had to learn by rote other older singers' ways, till I could absorb and express my own notions of appropriate and permissable style and interpretation. Then I listened to learn while somehow editing down the other singer's personality and highlighting for myself the core of the song.