Wild Blue Pixel
TIP OF THE DAY
Friday, January 5, 2007
An interval of one octave is made by doubling the frequency. An octave above A 440 Hz is A 880 Hz. An interval of a "perfect 5th" (which you may know from my books as the backbone of most chords) is made by multiplying the starting frequency by 1.5 - and you can understand where this comes from by going back to look at the vibrational modes of a string.
As you can see, the first harmonic has a wavelength half as long as the fundamental - as the wavelength and frequency are inversely related, cutting the wavelength in half multiplies the frequency by 2 - i.e., an octave. The 2nd harmonic has a wavelength 1/3 times the fundamental's wavelength, so its frequency is 3 times higher than the fundamental's frequency - or, its frequency is 3/2 (1.5) times higher than the 1st harmonic. These two harmonics make the interval of a perfect 5th.
If you know music a bit, you know if A is 1, B is 2, C# is 3, D is 4, and E is 5 (just going up the scale in the key of A). Hence, the frequency of E should be 1.5 x 440 Hz = 660 Hz. Actually, when I look up on my chart, I see that E is really 659.25. Why the difference? Because that is a "tempered 5th", not a "perfect 5th". Huh? Come back next Friday, we'll be on the road to understanding this.
NEWS from the KALIMBA MAGIC SHOP
Hugh Tracey Prices Are Going Up
Purchase now and pay 2010 prices.
The dollar has fallen by 15% with respect to the South African Rand over the last six months, which means Kalimba Magic is now paying about 15% more in U.S. dollars for each Hugh Tracey Kalimba.
So don't tarry over that order, purchase your Hugh Tracey Kalimba before we recalculate our prices for 2011!