sound from an organ comes from of a
set of pipes of different lengths, through which air is blown. The instrument is
controlled by a keyboard resembling a piano keyboard. Large organs usually have
two keyboards and a set of foot pedals arranged in the same manner as the piano
keys. Traditional church organs used mechanical bellows to generate the
wind, but modern ones use electric fans.
keyboards are called manuals, and the foot pedals are called the pedal-board.
Traditional organs also have a set of stops, which are knobs connected via
levers to sliders which open or close ranks (or groups) of pipes. In this way,
depressing a single key on one manual may sound several pipes
simultaneously. Different stops open different combinations of pipes,
creating differing sound qualities or timbres.
Since the invention of the
electronic oscillator, modern electric organs have been developed which simulate
the sounds of traditional pipe organs quite successfully. Even more
realistic today are the sampled organ sounds used by modern digital keyboards
and digital synthesizers.