Museu Nacional de Etnologia, Lisboa

The African collection of the National Museum of Ethnology is one of the best in the world. So much so that the Museum of African Art in New York has held a major exhibition exclusively with the African pieces from the National Museum of Ethnology. But, despite the invaluable value of this collection, some of its pieces are only 10 years old. What makes a drum, a mask or a pot lid valuable?