It is a spectacular museum and can take many hours to go through depending on your desire for detail. I am taken aback at an entrance fee of $20 as it limits who might go to visit it.
I dislike the atmosphere of exclusiveness that places like this have taken on, but it does not make the museum less grand.
I was excited by seeing the various instruments. The Paraguay junk yard orchestra is very inspiring.
Note that it can really teach geography as well, as the maps, particularly of Africa are up to date. Culture as well as music is implied by the displays.
Worthwhile to visit. Spend time;get your money's worth.