Cultural purveyors from Garrison Keillor to T Bone Burnett to Billy Bragg have hailed The Milk Carton Kids’ importance among a group of new folk bands, both expanding and contradicting the rich tradition that precedes them. Yet while some of the band’s many accolades reference a specific genre, the duo quickly transcends those tags with clear inflections of jazz, classical, even the dark lyricism of modern “alternative.” The grammy-nominated harmony duo have just released their third album, Monterey. A refreshing alternative to the foot-stomping grandeur of the so-called “folk revival,” an understated virtuosity defines The Milk Carton Kids and their new album.