From shouters to chanteuses, R&B melisma to the high lonesome sound of bluegrass, this week we bring you some of the biggest voices on the American soundscape. Neo-retro vocalist k.d. lang comes by to talk about her loves and influences from ’50s country to smoky lounge music. New Orleans singer Topsy Chapman tells us how a stint as a singing waitress on Bourbon Street and growing up with 15 siblings led her to an international career as a song stylist.