The organ is a wind instrument that evolved from the pan pipe and dates back as far as the 3rd century BC. Organs first arrived in Europe during the 8th and 9th centuries when they were exported from the Byzantine Empire to France.
The organ has developed over time so that the modern pipe organ is now a large complex instrument with multiple manuals (keyboards) and pedals and possesses the greatest range of any instrument.
The sound is produced from many pipes of various sizes under the application of compressed air produced from bellows. The pipes are grouped into stops, which are ranks of pipes prepared to speak by a knob and correspond to a type of sound that the organ can make. Each stop consists of pipes that range in size from short to tall, the taller the pipe the lower the note. Each stop is arranged in parallel to other stops with pipes that produce the same note adjacent to that of another stop.
The 20th century saw the organ evolve again to become an electro-mechanical instrument. Those, such as the Hammond Organs as seen in large cinemas during the 1930s included sound effects and colour displays.
The word organ is also a euphemism for penis allowing for double entendres in the text of Cryptonomicon about playing the organ.