Most older bisonoric instruments made in Germany are labeled with numbers
and symbols. They where introduced with the first instruments as an aid
for learning to play the instrument and identify the buttons. The first
instruments with two or three rows used only numbers but when extensions
were made the numberings had to be replaced by symbols or combinations
of numbers. A new button e.g. located between 1 and 2 was labeled 1/2.
The system does not follow a musical sense and was used for the
cipher notation called
Waschleinensystem (clothes line system)
which led to special music
editions for bandoneon, thought mainly for musical illiterates.
It consisted of the sequence of the key codings on one single line
giving instructions about the timing. There are still some old bandoneonists
in Germany using the system.
From the next section you may access to some keyboard graphs in which it will be refered to this codings, particularly to explain how the keyboard systems evolved with the time.