The entire system of an organ is called disposition . This is made up of the individual registers , but also of technical details such as the type of playing and register action, manual distribution, playing aids and the tuning used .
The disposition for each organ is created individually by the organ builder in consultation with the client and the organ expert and differs in its basic features in different epochs and currents in music history. Practical conditions such as the purpose of use, acoustics of the existing room, available space and, last but not least, the financial possibilities are further relevant aspects. If necessary, the guidelines for monument protection must also be observed.
Since each organ is usually designed and built specifically for its location, there are hardly any organs with absolutely identical dispositions. Small organs ( positive , portative , shelf , small house organs ) are an exception . These instruments are not built for a specific room because they are transportable. Likewise, the positives built as chest organs are transportable. Small organs are sometimes manufactured in small series with always the same disposition.
The historical development of the disposition is described in the context of the historical development of the organ .