The bandoneon is a musical instrument of the family of the concertina. It was introduced in the Rio de la Plata region at the end of the 19th century and became an essential component of the tango orquesta in the early 1900’s. It remains to this day the most emblematic instrument of tango music.
Created in Germany around 1845, the concertina was conceived as an alternative to the organ amd meant to be used for religious services. It is not clear who first invented the bandoneon but it is has been attributed to Carl Zimmermann, the fabricant who sold his manufacture to Ernest Louis Arnold, creator of ELA bandoneons. Ernest Louis Arnold was the father of Alfredo Arnold who later produced the bandoneon “doble A”, a brand highly praised by tango musicians.
The first documented mention of a bandoneon being played in the Rio de la Plata is from a newspaper article by Jorge Labraña published in 1895. According to this article the bandoneon was brought to Uruguay by a Suiss immigrant in 1863. Other sources indicate that it was imported by an Englishman, Don Tomas, who came to Argentina in 1884. 
One of the first musicians to incorporate bandoneon to tango is Domingo Santa Cruz. Santa Cruz used to perform in the cafes of La Boca and Barracas in the early 1900’s. Other bandoneonistas of the first generation are Genaro Esposito, Vicente Loduca, Eduardo Arolas, Vicente Greco and Juan Maglio.
The inclusion of the bandoneon in tango bands had profound repercussions. Before the bandoneon, tango was usually performed by small bands composed of guitars, flutes and violins. The adition of a bandoneon brought deeper tones and a slower pace of execution. It also created a distinctuon between bands which were dedicated to tango and other bands. It eventually replaced flute and became a essential component of the orquesta tipica. 
Because manufactures in Germany have been closed for over 70 year, bandoneons are now rare and expensive instruments.  New artisanal bandoneons have been built lately but the process is long and complex and remains expensive.
The first bandoneon made in Argentina was released in 2000. The bandoneon AZ was built by Argentine luthier Angel Zullo and introduced to the public on the day tango was officially declared world heritage by the UNESCO. 
Bandoneons were built to last 200 years with proper maintenance.
 Zucchi, Oscar. El tango, el bandoneón y sus interpretes. Buenos Aires: Corregidor, 1998. Print.
 Pesce, Ruben, Oscar del Priore, and Silvestre Byron. La Historia del Tango: La Guardia Vieja. Buenos Aires: Corregidor, 1977. Print.
 “Salvar el bandoneón”. La Nación. Web. June 26, 2009. Online. https://www.lanacion.com.ar/1143843-salvar-el-bandoneon
 “Empezó a sonar el primer bandoneón nacional” La Nación. Web. Oct 3, 2009. Online. https://www.lanacion.com.ar/1181690-empezo-a-sonar-el-primer-bandoneon-nacional