In the early 19th Century, the Tango was a solo dance performed by a woman. The Adualisian Tango was later done by one or two couples walking together using castanets... and was considered immoral.

The dance we recognize today as Ballroom Tango originated in the "Barria de Las Ranas", a Buenos Aires ghetto. Originally it was called "Baile con corte" (dance with a rest.)
Tango oral history has it that Argentina's gauchos, wearing chaps that had hardened from the foam and sweat of their horse's body, generally were forced to walk with knees flexed. They would go to crowded nightclubs and ask the local girls to dance. Since the gaucho hadn't showered, the lady would dance in the crook of the man's right arm holding her head back. Her right hand was held low on his left hip, close to his pocket looking for a payment for dancing with him! (The man danced in a curving fashion because the floor was small and littered with round tables, which he danced around and between.)

The dance spread through Europe in the 1900's. Originally popularized in New York in the winter of 1910-1911, Rudolph Valentino made Tango a hit in 1921.

Time passed and the music became more subdued. Tango dance finally attained respectability, even in Argentina.

Styles vary: There is the Argentine, French, Gaucho and International, but the Tango has become an American 'Standard' regardless of its origin. The Americanized version is a combination of the best parts of all the tangos.

Phrasing is an important part of Tango. Most Tango music is phrased to 16 or 32 beats of music and is a story. It contains paragraphs (Major phrases); sentences (Minor phrases) with the period at the end of each sentence the three beat "Tango, close."