The pipe organs found in concert halls are large scale instruments, with many metal pipes. Only some of these are visible, but back-stage there are actually many thousands of pipes – almost like a forest.
The reason several thousand pipes are needed is that one pipe can only produce one sound. One pipe might produce only a C-pitch sound with the timbre of a flute, for example, while another might be made to generate only a D-pitch sound with the timbre of a trumpet.
With a range of 56 notes from the lowest note to the highest, 56 pipes are required for each timbre of sound desired. In a case where 3 different timbres are sought, perhaps for a trumpet timbre and a flute timbre, three times as many pipes as the number of distinct tones in the range are required, making a total of 168 pipes.
This is to say that the more timbres of sound available on the organ the more pipes it needs, and the more gigantic it becomes!