You can see the 1905 National Songbook...edited and arranged for the use of schools online. I think similar books always existed. And there was the BBC Singing Together series from my childhood with a large proportion of British folk songs.

As regards the vocal styles, it's very much a matter of your expectations. Listening conditions us to a certain expectation of how things should sound. We have a certain conception of how folk songs should sound, a different one for how a jazz song should sound or lieder or opera. Remember the conflicting opinions when Sting sang Dowland about whether his voice was right for it. Hearing concert sopranos or tenors do pop songs usually sounds odd because stylistically it's not the usual way we hear them. If you're used to hearing recordings or live performances of folk songs by traditional singers you're going to find Peter Pears' version odd. (And by the same token, if you've only heard folk songs sung by classical concert performers you're probably going to find a version sung by Phil Tanner or Walter Pardon equally strange).


BBC4 had a programme on not long ago about Gershwin's Summertime, which I think had some 25000 cover versions in styles ranging from opera to jazz to pop to hip-hop I think, several of which were played during the programme. The song was adaptable to a wide variety of interpretations; but particular audiences would find some styles acceptable, some anathema. Same with folk songs; hearing context colours our expectations.


Mick