Unisonoric bandonion or bandoneon

The unisonoric bandoneon was developed using the mechanical construction of the bisonoric bandoneon, which dates back to the German concertina invented by C. F. Uhlig of Chemnitz in around 1835. Later, in 1849 at the Industrial Exhibition in Paris, C. Zimmerman of Saxony exhibited the Carlsfelder Konzertina. However, the instrument came to be associated with Heinrich Band, an instrument dealer from Krefeld who advertised this instrument or similar, which came to be known as a bandonion. Whilst easy to think that the name is a fusion of the dealers surname "Band" and the word "accordion", it apparently comes from the name used to advertise the instrument "Band Union".

The great popularity of bandoneon in the 1920s led to French musette accordion players wanting to learn the bandoneon but without the complications of the bisonoric layout. Around 1925 Charles Peguri designed the unisonoric bandoneon, using the same construction as the bisonoric bandoneon, but using a button-field that comprises a nucleus of 3 rows based on the international chromatic system, as found on accordions, alongside another three rows of other notes that extend the range of the instrument and make it easier to play certain very broad chords that can easily be played on the bisonoric system, but not so easily on the chromatic system, especially when only using four fingers as on a bandoneon. This instrument is still particularly popular amongst bandoneon players in France.

The unisonoric bandoneon is, undoubtedly easier to learn than the bisonoric bandoneon, but does inherit the uncomfortable, cramped fingering style of the international chromatic system and has a split personality, having an isomorphic, regular nucleus of 3 rows based on the international chromatic system, as found on accordions, coupled with an irregular, non-isomorphic extension, which is a hinderance to rapid learning. In this respect an Atzarin bandonion is a better option.

Although "bandonion", the original name comes from German it is the Spanish spelling, bandoneon, with or without an accent, that is most commonly used in English texts. On this web site the Spanish spelling, bandoneon, will be used to refer to the traditional 71 button bandoneon, whether using the bisonoric Rheinische layout or a unisonoric Peguri layout.