Mrs. and Mr. Vernon Castle:
They were just about the best dancers of their time, but even with plenty of hype and a wide open field in learning, they had little knowledge of Dance history.
Quote from the Castles:
“The Tango is not, as commonly believed, of South American origin. It is an old gypsy dance which came to Argentina by the way of Spain, where in all probability it became invested with certain features of the old Moorish dances. The Argentines adopted the dance, eliminating some of its reckless gypsy traits, and added to it a certain languid indolence peculiar to their temperament.”
"Nostalgias" by Placido Domingo
They were referring to the old Andalusian tango which of course had nothing at all to do with the Indian Milonga being danced in Argentina for ages. The Negros being in the servant field picked up on it and there is a famous painting of the Negros dancing.
It is entitled, "El Tango De Los Negros" meaning the Tango of the Negros (their version of the Andalusian Tango) and the date on it was 1832. So some will even go so far as to tell you that is the proof that the Negros were dancing Tango before the Argentines. Which is true, semantics wise. But they were not dancing the Tango that is today's.
"La Media Luz" by Julio Iglesias
The Andulasian Tango danced by the uppercrust lasted only a two or three decades (one generation) before becoming extinct. It lasted longer with the Blacks. But of course, they had fewer choices. The Tango is riddled with inaccuracies picked up in error along the way. Even those that say it is whorehouse dance and danced to whorehouse music do not tell you all the facts. That was the Milonga and it is not the complete story.
We will uncover more inaccuracies as we go along. For instance, you cannot have Tango without a Bandoneon and the Bandoneon did not arrive unitl the late 1850s. That slowed the entire Milonga down somewhat. The former merry rhythms became slower and sadder. But then, there are some disciplines that dance their versions of tango without ever coming close to a Bandoneon. For them, the tango is the "real" thing without.
Late in the 1890s because of the bad reputation of the Milonga, the dance powers decided to change the name to Tango. But it remained Milonga - Tango for 50 years.