Singer-songwriter Loudon Wainwright III and Nighthawks bandleader Vince Giordano collaborated on the 1920s and '30s style music for the series 'Boardwalk Empire' and the film 'The Aviator.' Now they've gotten together again on the new album, 'I'd Rather Lead a Band,' a collection of songs from the Great American Songbook. They talk with Terry Gross about their new record and the music of the era.