The antique Argentine Tango was influenced by the Tango Habanera, which bears no resemblance to the Argentine Tango we know today.
The Tango Habanera came about from two types of Tango: the Milonga with its influence in the guajira flamenca and the Tango andaluz or Tango flamenco.
The Milonga was danced and played by country side people of Argentina. The Tango Habanera was an amalgamation of the Habanera and the Tango Andaluz or Tango Flamenco.
The rhythm of the guitars playing the Tango flamenco or andaluz could not be reproduced in orchestra instruments and with the piano, so the Tango andaluz or flamenco was modified with the habanera rhythm.
The Tango Habanera was heard in 1883 but died towards the end of the century. The Tango Habanera has been entirely associated with the first forms of Argentine Tango.
The flexing of the knees is associated to a dance called Candombe which was danced by the black people from Africa living in Buenos Aires. The male Candombe dancers danced with their knees flexed, to show their dance skills using walking steps (corridas) and turns.
A character who lived in the very early 1900's known as the "compadrito" created the straightened out forms of the antique Argentine Tango and invented the traditional figures of this dance. His dance style and stance supported his macho view of his world at those times.
The "compadrito" ironically imitated the Candombe Dancers along with their flexing of the knees, walking steps, and turns.
Old Tango people agree that the true forms of Argentine Tango Dance that we see today originated in 1938 - 1940 with the short-lived Tango singer Carlos Gardel.
The Golden Age of Tango took place in in the late 1940's and early 1950's. World recording companies set up offices in Buenos Aires, which resulted in mass recordings of Tango orchestras and singers.
The antique Argentine Tango was never danced with castanets or with a flower.
Today in Buenos Aires or Río de la Plata, there are three forms of Argentine Tango: Salón, Fantasía, and one for scenario (stage). This has been the norm. With the internationalization of Tango, other forces have been shaping the Tango dance.
The form known for stage, sometimes is referred as "for export", was aimed at English speaking people.
Outside Argentina, people from North America had their first exposure with Stage Tango brought by the show and dance companies from Buenos Aires.
At the end of the shows, the people asked for classes on what they had seen on stage. They wanted to learn what they saw on stage. Some of the dancers were available to teach, but knew only show routines.
Other times seasoned dancers from Buenos Aires were asked to teach. They found it very difficult to explain that the correct form was to learn Argentine Tango from Buenos Aires rather than what they had seen at the show or on stage.