Johann Gottfried von Herder (25 August 1744 – 18 December 1803), a German philosopher, theologian, poet, and literary critic, was the first person—as far as anyone knows—to use the word(s) "folk song." He was suggesting to composers that if they wished their music to reflect the national character of their country, they should study the country's volkslieder (folk songs).

Sounds to me like he was suggesting these composers should go and write a new folk song, Don!