1989’s Big Daddy finds John Mellencamp fully embracing his role as a populist troubadour. Though his customary rock swagger is still present, there’s a humble, compassionate quality to these songs that’s more reminiscent of Woody Guthrie than Keith Richards. Mellencamp has a good deal to say about America’s neglected underclass here, whether represented by hard-pressed family men (“Jackie Brown”) or teenaged misfits (“Theo and Weird Henry”). He dispenses folk wisdom in “Sometimes a Great Notion” and calls out corporate America in “Country Gentleman.” Getting personal, he reflects upon his own experience in the clutches of showbiz in “Pop Singer.” Such heavy themes go down easy thanks to the spirited, acoustic-rooted backing of Mellencamp’s band, with violinist Lisa Germano and accordion player John Cascella adding particularly tasty licks. Self-produced by Mellencamp, Big Daddy is serious-minded without being overly sober and loose without being ragged. This is Middle American folk-rock with a conscience, served up with plenty of heart.