At a press conference for his new Crosby Stills Nash & Young documentary at the Berlin Film Festival recently, Neil Young told reporters that “the time when music could change the world is past.” It’s time for science and spirituality so save the planet, the 62-year-old songwriter added. Perhaps Young is on to something. Or perhaps music plays an indirect role in social or political change. Tim Riley, music commentator for NPR’s “Here and Now” and author of “Fever: How Rock ‘n’ Roll Transformed Gender in America” joins us.