Neither country nor folk, but reminds me of the popular musician NeilCicieregaMusic, who did mashups of songs in a similar way. His more recent stuff has moved further into the "meme" music territory than this, but a few good examples: Crocodile Chop (mashup of Elton John's Crocodile Rock and System of a Down's Chop Suey!) or Close to the Sun (a mix of The Carpenters' Close To You and Soundgarden's Black Hole Sun)