You call the first theme folk melody...that's a compliment; I thought of it as a fugue subject in disguise! There are romantic-era nods as well. In the first movement, the slow intro sounds a bit like Tchaikovsky, and the final cadence is a direct rip-off (well, tribute to?) of the final cadence to C.M.V. Weber's Der Freischütz first act! Different key. It has always been my favorite opera!😉
It is not postmodern, but could that be true in a way? Basically a Nineteenth Century symphony, but has Baroque elements, even some Classical ones. We LIVING composers have the luxury, especially today with everything on the Internet, to be eclectic.