In Argentina the orquesta típica is an orchestra specialized in performing tango. It is composed basically of two bandoneones, two violins, piano and double bass.
Before the first orquesta típica were formed, tango was 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 or played on the organito.
The incorporation of the bandoneon in tango instrumentation around 1910 was an important event in te evolution of tango instrumentation. First of all it had a profound effect on the sound and feel of tango music.  Also it sets apart bands which were dediated to the tango criollo as the bandoneon was rare and difficult to play.
The expression “orquesta típica criolla” first appeared on Columbia labels in 1911. It is is attributed to Vicente Greco, bandeonista and orquestra director who used it to identify his band as one which specializes in tango.
The 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.