The orquesta típica in Argentina is a an orchestra specialized in performing tango. It is composed essentially of a two bandoneones, two violins, piano and double bass.
Before the orquesta típica was fully formed, tango used to be improvised or played by ear on commonly available instruments such as guitars, violins and flutes. The simple structure of the first tangos allowed for musicians to perform them on their own or in small bands of two to four musicians.  Tango was also performed by municipal, military and police bands.
The incorporation of the bandoneon in tango instrumentation around 1910 had a profound effect on the sound and feel of tango music.  It also creates a distinction between bands which specialized in performing the tango criollo and others which performed other rhythms as well since the bandoneon was not a common instrument and a difficult one to play.
The expression “orquesta típica criolla” first appeared on Columbia labels in 1911. It is is attributed to Vicente Greco who used it to distinguish his orchestra as one which was specialized in tango.
These first orquestas típicas were mostly cuartetos composed of guitars, violins, flutes and bandoneon.  The piano and double bass were included shortly after by Roberto Firpo and Francisco Canaro to complete the creation of the typical sexteto. π
 Pesce, Ruben. La historia del tango: La guardia vieja. Buenos Aires: Corregidor, 1977. Print.
 Zucchi, Oscar. El tango, el bandoneon y sus interpretes. Buenos Aires: Corregidor, 1998. Print.