Organ action: organ internal operation.
Pipe: cylinder equipped with a whistle or a reed.
Rack board: pierced board that maintains the pipes vertically.
Upper board: pierced wooden piece that receives the pipes base to prevent the air from escaping.
Slider: allows to choose the pipes row and the notes to be heard.
Valve spring: spring that allows to open or close a valve.
Wind trunk: pipes that brings the air towards the slider.
Stop rod: mechanism allowing to operate the slider.
Tracker: mobile rod linking the key to the valve.
Key: part of the keyboard that is pressed to produce a note.
Valve: trap that is operated to get a note. There is a valve for each note for each keyboard.
Bearer: guides between which the slider is slided.