The often-imitated Iris DeMent hits her notes in ever-wavering bursts of energy that never fail to convey the sort of sincere emotion that keeps folk fans hugging her records since the very first track, “Let the Mystery Be." But whether you prefer her vocalizing heart-wrenching insights on My Life, getting politically charged on The Way I Should or partnering up with John Prine for some of country’s cheekiest duets, you likely lost it when she bounded back in 2012 to release Sing the Delta, her first record in eight years and her heftily praised return to songwriting after 16 years.