Gregory examines how early 20th-century blues growlers like Bessie Smith paved the way for the rhyme and flow of hip-hop, how truth became a quest of rock 'n' roll's greatest poets from Woody Guthrie to Gil Scott-Heron, from Lou Reed to Suzanne Vega, and why great popular voices, including Bob Dylan, Leonard Cohen and Kurt Cobain, don't have to be technically perfect to resonate so deeply and stir our souls. With Dave Grohl, Suzanne Vega and KRS-One. Show less