> some mediators run the risk of/have misrepresented working-class life as lived.

Few (if any) song mediators have been sociologists or anthropologists , or even thought of their work in those terms, so this is a bit like criticizing novelists, perhaps, for not being academic postmodern theorists.

I'd expect that an understanding of working-class life must rely far more heavily on other sources than tunes and songs - though those sources would obviously include non-musical lore.