The Country Music Hall of Fame’s upcoming exhibit, Outlaws & Armadillos: Country’s Roaring ’70s, will explore the era of cultural and artistic exchange between Nashville, Tenn., and Austin, Texas, that spawned artists like Willie Nelson, Waylon Jennings, Kris Kristofferson, Jessi Colter, Bobby Bare, Jerry Jeff Walker, David Allan Coe, Cowboy Jack Clement, Tom T. Hall,…