The zarzuela is a form of Spanish musical theatre which played an important role in the gestation and popularisation of Argentine tango. In the early 19th century it introduced the tango andaluz to the city of Buenos Aires, and later offered a platform to showcase Argentine tango as a new independant musical genre.
The first documented mentions of a zarzuela goes back to 1657 with the premier of “El golfo de las sirenas” by Calderon de la Barca. The term zarzuela comes from the name of the royal theater in Madrid where this type of musical play first appeared.
In the 19th century a short version of the zarzuela was created, the genero chico, which was more affordable and became popular in Latin american countries including Cuba, Venezuela, Mexico and Argentina. These short comedies were usually composed of a single act and lasted an hour or less. They were often inspired by sainetes, another genre of short musical play which also contributed to the evolution of tango later in the 1920’s.
One of the ways in which the zarzuela influenced the evolution of tango is by introducing the tango andaluz to the city of Buenos Aires. Theaters were an important vehicle for songs to be popularized and the tangos andaluces not only became familliar to the porteños but soon inspired new local songs.
These so called “tangos criollos” did not yet constitute a distinct musical genre but a are regarded as one very primitive form Argentine tango. An excellent exemple of such “tango criollo” is “Andate a la Recoleta” (1800), which is little more then a tango andaluz with adapted lyrics reflecting the reality of life in the new world.
Another way in which the zarzuela played a role in the evolution of tango is by providing a platform in the late 19th century to present and popularise the new Argentine tango. The first documented use of the word “tango” in the sense of tango porteño was found in the script of “Justicia Criolla”, a local zarzuela which featured the new musical genre and dance.
 Pellettieri, Osvaldo. Historia del teatro Argentino en Buenos Aires. Editorial Galerna, 2002. Print.
 “El dia que el tango tuvo nombre”. Clarín. Online. https://www.clarin.com/espectaculos/dia-tango-nombre_0_S1luFxZRKx.html