On Thu, 7 May 1998, Colin Wood wrote:

> SamMaEl wrote:
> > 	"Higher" frequency, lower pitch. Just like when you pluck a

Uhm, that's "higher" frequency, higher pitch, and shorter wavelength.

> > string, then shorten the string by a half, the note will sound an octave
> > higher. Or, so said Pythagoras. And just the same, cutting the
> > frequency in half raises the pitch an octave. So, 880 Hz would be the A
> > above middle C, and 440 Hz would be the A an octave higher than the 880 A.

You're right about shortening the string raising the sound an octave
(though I didn't know Pythagoras said it). But when you shorten the
string, you shorten the sound's wavelength, not its frequency. When you
halve the length of the string, you halve the wavelength, and double the
frequency.

Remember, (frequency)*(wavelenght) = speed of wave (sound here, but true
for light also)

Also, 440 Hz is (about) the frequency of the A above middle C. In some
tuning systems, middle C is 256 Hz (and the A just above middle C isn't
440), and in other tuning systems, like "A 440", that A is 440 Hz, and
middle C is not quite 256. 

Take care,

Bill