One other thing about the title Ouro Negro. In Portuguese the word for the color black is preto (I was just in the town of Ouro Preto last week). Negro, which in Spanish is the color black, in Brazil is used as a racial term only as far as I know, people may call them self negro or negra, so it's even more of a play on words. There's a DVD of a performance of the music with some of the guest singers, but I haven't seen it.