MOTM

Comments in line.

paulhaneberg wrote:
 >
> If I remember correctly an open organ pipe resonates at the 
> wavelength equal to the length of the pipe.  I think a pipe closed 
> at one end resonates at a frequency of either twice the wavelength 
> or half the wavelength, I can't remember which off the top of my 
> head.

It resonates at twice the wavelength, half the frequency, or one octave 
lower.

> A 64' pipe would resonate at 17.65 Hz.  
> A 1' pipe would resonate at 1130 Hz.

One octave off (reference A440):

64' (CCCCC Speaking length) is 8.175 Hz
32' (CCCC Speaking length) is 16.35 Hz
  1' is 523.2 Hz

Remember, this is all speaking length. The scale of a pipe with varying 
width and depth will affect the height of the pipe. In other words, a 
wider/deeper pipe of the same length will sound lower that a narrower one.

> One other interesting bit of organ trivia.  
> Typically you would have multiple stops open at any given time.
> Every note has a corresponding pipe for each stop.
> So if you had a pipe organ with 25 stops for the "Swell" keyboard 
> you would have 1525 pipes!!!

Some stops bring more than one rank into play, perhaps as many as 8, 9, 
or even 10 pipes on larger instruments for a single stop pulled. With 
couplers drawn and full organ, I have heard large instruments that could 
have as many as 500 pipes play with the press of a single pedal key!

Regards, Scott