My Morning Jacket’s fourth studio album focused the reverb-saturated grandeur of their early records into a contemporary slant on classic Americana—from Neil Young to American Beauty-era Grateful Dead to the wistful side of Elton John. On Z, the band grow into their loopy sense of humor, too, as they balance the expansive earnestness of songs like “Lay Low” and “Wordless Chorus” with the group shout-along “What a Wonderful Man” and some weird Appalachian reggae on “Off the Record.”