JOHN HIATT At 60, the master singer-songwriter still follows wherever the music leads After 40 years and 21 studio albums, John Hiatt knows a thing or two about songcraft. On his new album,  Mystic Pinball, he even manages to make a grocery list interesting, wrapping it up in the grisly story-song, “Wood Chipper.” “It’s a bit of an homage to the Coen Brothers and the wood-chipper scene in Fargo,” he explains. “I started playing the...