Only Mississippian Jimbo Mathus and Chicagoan Andrew Bird could compose an album so different from their platinum-selling Squirrel Nut Zippers’ roots, yet with the same sense of tender nostalgia that will endure until the end of time. Co-written and performed exclusively by the two of them, their new record, These 13, is undoubtedly American folk, an homage to tradition, songwriting, and a sound embodying an endless optimism, even in its most sentimental songs. This is the kind of album you’ll listen to over and over, because it adapts to every phase, every mood, each lyric laced with heart-wrenching and, sometimes, lighthearted simplicity. It’s a museum-worthy, American-quilt-apple-pie comfort, perfect for our times right now. “I’ve never made a record that was more fun to make and as eas...