Every year the National Recording Registry at the Library of Congress selects 25 recordings to be preserved for all time. One song chosen this year is “O Que è Que a Bahiana Tem,” a samba recorded by Brazilian singer Carmen Miranda in 1939. Dori Caymmi, the son of the songwriter, and biographer Martha Gil-Montero explain how the song brought Brazilian music to the global marketplace ? with unforeseen consequences for Miranda.