Over a half century ago, Ramblin' Jack Elliott became Woody Guthrie's sidekick and leading interpreter, and later a hero to Bob Dylan and the early '60s folk scene. At 77, Elliott (born Elliot Adnopoz in Brooklyn) still lives up to his nickname. Ask the San Francisco-based urban cowboy a simple question — for instance, how Joe Henry came to produce Elliott's new album of Depression-era blues, A Stranger Here — and he'll embark on the first of many detours through his long and...