Now that the ritual of listing the best music for the year has drawn to a close, it’s worth questioning the over-the-top praise heaped upon the second album by this artist, who also goes by the name Justin Vernon. While the Grammy-nominated “Holocene” is a gorgeously meandering piece of lush chamber-folk, the album is wildly uneven, especially “Beth/Rest,” a bafflingly straight-faced homage to ‘80s smooth-pop cheese.