This way it is possibleto change and vary manuals:
- to connect and disconnect the manuals
- to mix, contrast or change different sound characters
- to make sound silent or loud by using the swell works
- to make the quantity of the sound continuously increase or decrease
The tracker connects the console to the organ case. It forwards the information by mechanic, pneumatic or electrical action.
The pipes are the sounding devices of the organ. They can be activated by the stops and the keys. (Picture 7)
Pressing a key would activate the corresponding pipes. Each manual has its separate keys and groups of keys.
The basic constituents are the pipes that can be made of metal or wood. The metal pipes are made of a mixture of tin and lead and they are cylindrical. The wooden pipes are constructed of sheets of wooden board and are put together in a rectangular shape. (Picture 8) They are characterized by their measurements which is the proportion between their length and their diameter. The length of a pipe would determine the level of pitch, their width is responsible for the fullness of the sound, the strength of the wind would determine the intensity of the sound and other constituents control the tone quality.
The ranks of pipes own different tone production method, different form of oscillation, length and shape, they have different material, size and voicing.
Their difference would show in tone quality, tone density, tone strength, and level of pitch.
Flue pipes – Their action and structure is similar to the one of the recorder. Their size may vary from 10 centimetres to 10 metres. They can be either open or stopped (gedackt). The stopped pipes would give a sound of one octave lower with the same dimensions.
Reeds – They consist of a metal reed which is resonated by the wind like in a harmonica. They are added a resonator of different type.
The pipes stand in the wind chest where the wind pressure is measured by a gauge and the density of the wind is controlled in many stations. The wind chests that provide wind to the works, and the pipes, and the ranks of pipes are called slider chests.
The tone of each pipe and rank of pipes is intonated according to balanced proportions and past experience depending on their power, tone quality and expression. This process and its result are called voicing. After certain preparations in the factory, voicing is an artistic activity that can be completed only on the particular site.