Pipe Organs By: Kelsey Aadland

1. Pipe Organs By: Kelsey Aadland

2. Historically, • Pipe organs stretch back to around 200 B.C. • Ctesibius of Alexandrea is generally credited with building the first pipe organ, the hydraulis. • He employed an ingenious system using water pressure to regulate the air pressure which may have been pumped by a windmill.

3. Modernly, • Pipe organs consist of : • Keyboards, called manuals • Set of pedals • Complete sets, or ranks of pipes • Windchest (reservoir), which holds compressed air to flow into the pipes and • Stops, which are levers that control which ranks are actuated by each manual

4. Pipes • Organ pipes are made from either wood or metal and produce sound when wind is directed through them. One organ pipe produces one tone at one pitch, and since there is just one pipe for each note, a keyboard with 61 notes (5 octaves) would have 61 pipes, one for each note. The one set of pipes for each note on the keyboard makes just one kind of sound. The organ will have several sets of pipes; which as stated before are called “ranks”, which can make different sounds.

5. The volume of the sound produced by a pipe depends on the pressure of the wind flowing to the pipe and how the pipe is voiced (adjusted by the builder to produce the desired tone and volume). Thus, a pipe's volume cannot be changed directly while playing. • Organ pipes are divided into flute pipes and reed pipes according to their design and timbre. Flue pipes produce sound by forcing air through a fipple, like a recorder, whereas reed pipes produce sound via a beating reed, like a clarinet.

6. To make sound, • An organ contains two actions, or systems of moving parts. When a key is depressed, the key action admits wind from the windchest into a pipe. The stop action allows the organist to control which ranks are engaged. An action may be mechanical, pneumatic, or electrical.

7. How it works • The air enters through the bottom of the pipe and hits the sharp edge at the front of the pipe making the air vibrate. Those vibrations that do not fit exactly in the pipe drown themselves out as they interfere with themselves. In the animation on the left, the blue curve is the wave that bounces up and down in the pipe, and the red curve is the net result: the sum of the blue curves.

8. The length of the pipe determines which waves fit exactly inside and thus the pitch of the tone the pipe makes. Several wavelengths fit—the pictures to the right show the first few. The blue curve is the primary tone, the remaining curves are overtones.

9. http://www.youtube.com/watch?v=rhakZPMjPKE

10. Fun fact • The largest pipe organ in the world is located in Philadelphia, PA. (In a Lord & Taylor Department Store.) • It has: • 461 ranks • 6 manuals • 28,482 pipes

11. Sources • http://lawrencephelps.com/Documents/Articles/Beginner/pipeorgans101.html • http://www.virtualorgan.com/default.asp?page=116 • http://www.danishchurch.vancouver.bc.ca/history/organ.html • http://en.wikipedia.org/wiki/Pipe_organ#Pipes • http://theatreorgans.com/laird/top.pipe.organs.html