The bandoneón, so named by the German instrument dealer, Heinrich Band (1821–1860), was originally intended as an instrument for religious music and the popular music of the day, in contrast to its predecessor, the German concertina (or Konzertina), considered to be a folk instrument by some modern authors. German sailors and Italian seasonal workers and emigrants brought the instrument with them to Argentina in the late 19th century, where it was incorporated into the local music, such as tango. [via Wikipedia]
Would you like to have the Bandoneón in your NI Kontakt ? To be honest, I don't know if there are some other Bandoneon kontakt libraries but this one seems great (judging by audio demos, comments etc.).
This particular Bandoneón was recorded in Buenos Aires, Argentina by the renowned composer Guillermo Guareschi. It is a "Premier" Bandoneón with a sweet and expressive sound. One Neumann microphone was in charge of register for the left hand where all the bass notes are generated plus an additional ribbon microphone that handled the very low frequencies with precision. The right hand was captured by a modified SE A5600 II tube microphone and an AKG mic was set to record the natural high roof ambience of the recording studio. All the microphones were connected to vintage Telefunken preamplifiers that delivered the signal directly without any console or black box in the chain.
The library "weights" almost 800 mb, and requires full NI Kontakt 4.2 (and above).
Price ? 13.99 UK Pounds
More info: Sampleism - The bandoneon