Not sure about that, Pip: there was always an industry of 'arranging' folksong tunes for piano, or for drawing-room singing, probably from late-ish C17 on: think of Pepys back on 2 Jan 1666 hearing actress Mrs Knype at a musical evening singing her "little Scotch song" of Barbry Allen. There were always drawing-room versions. And, in Emma, remember that jigs and reels are played for gentry dancing by Mrs Weston in addition to the more formal dances of the time; and that gdentleman-farmer Robert Martin has his shepherd's song into the parlour to sing for his lady guest Harriet Smith. Wonder what he could have sung: Searching For Lambs, perhaps, whose erotic content, such as it is, is well subliminalised, and whose tune Vaughan Wiliiams {or was it Sharp} mentioned somewhere as the most beautiful he had ever heard. Always that sort of crossover. But it is the anachronistic use of the actual term folksong in 1803 that really jars. Bingley could reasonably have said something like "little Irish songs" or "popular airs", I think; and they might have been sung [in refined versions] or played on the piano, by the ladies after dinner among all the other things.

~M~