The real origin of Tango rests vague and uncertain.   

It is said that when the French colonists in the Dominican Republic (18th century), danced their “contre dance" (a French type of music where the tango's "counterpoint rhythm" would originate from), they were accompanied by music bands formed by their slaves.  Music that then would be influenced by Cuban music and the Spanish “zarzuela”.

The music was originally played on light and portable instruments: flute, guitar and violin trios, with the now so characteristic bandoneón only arriving at the end of the 19th century.  

We find the early Tango back in the streets of Buenos Aires, performed by the immigrants in Buenos Aires (the first generation of tango players being referred to as "Guardia Vieja"  or the “Old Guard”).   By the end of the 19th Century, it had slowly spread all through the city.

At that time a city with 100.000 men more then women, brothels had busy days where men of all social classes almost “lined up” for the girls.  In order to keep the entertainment going, the brothels owners (rich of money) hired live bands playing the exciting music that became even more sensuous and macho while the men danced with each other.

It took some time for Tango to move into more proper circles, but by 1920 people like Carlos Gardel introduced the tango-canción (lyrics) and this ultimately resulted in the "Golden Age" of Tango music (the period from about 1935 to 1952).

Beginning in France, Tango began to gain popularity in Europe (most of the time with the bandoneon exchanged for the accordeon), at approximately the same time.

By the end of the 1920's, Tango had moved out of the lower-class brothels and had become a more respectable form of music and dance.

Astor Piazzola – much to the dismay of the Tango purists – opened during the 1950’s doors to a more contemporary and popular form of Tango that ended up in a fusion of jazz / sometimes even rock music.  Nowadays it is called Tango Nuevo.  The so-called post-Piazzolla generation (1980-) even took Tango Nuevo one step further into a more experimental style.

Tango evolution has not stopped there.  Recent trends can be described as "electro tango" or "tango fusion", where “electronic influences” are sensible in multiple layers: from very subtle to dominant.  In general, they are grouped together under the denominator of Neo Tango.  Some performers still keep close to the Tango feeling by subtle use of electronic music elements (for instance Carlos Libedinsky and even Gotan Project), while others drift further away with more latin / salsa / electronic influences that more or less push the Tango backwards.  The new evolution is still in full development and vehement discussions are being setup by many traditional dancers who regard it as an inexcusable break in Tango tradition.