I don't know whether it matters what music is called, as long as it's good. Vaughn Williams, Copland and others take folk themes and turn them into 'serious' music.

Last night, I went to a concert that featured Willie Nelson with the Wynton Marsalis Band. Not a pairing I would have expected (Natalie Cole was supposed to appear). Nelson sang some of his hits in his current old man style, the band did jazz riffs...and the whole thing was good. But I don't know what to call it, or even if that matters.