Fado is the most Portuguese of songs, and often the most misunderstood. Visitors think it is a sad song, but that is a half truth. In fact, Fado can be sad and nostalgic, and that is cathartic to the listener. Fado is a purge of strong emotions. And, so in that spirit, we look into the soul of this ancient musical form, and find the 5 most mournful of Fados.