Way back in the late 1980s — the heyday of neo-traditionalist country as exemplified by Randy Travis and Ricky Skaggs — Lyle Lovett offered a jazzy variation on the formula. A songwriter who takes his cues from the likes of Guy Clark, Lovett is a singer of calculating charm and an often inspired cover artist, as his 1989 take on Billy Sherrill and Tammy Wynette’s “Stand by Your Man” demonstrates. His 1994 full-length I Love Everybody may be his most consistent record, but he continues to make adventurous music. Meanwhile, John Hiatt is, for better or worse, an American Elvis Costello minus the musical eclecticism — a somewhat marginal singer and a genius songwriter. Hiatt loves rock ’n’ roll for what it means for the larger American culture, and continues to write about the struggling American lower middle class without condescension.