What he's talking about is the presence of upper partials (harmonics). There's been a number of discussions about the harmonic series and how it relates to the fundamental, which is the note you want to measure. Basically, whenever you play a note, like a C for instance, there's a lot of other notes that are related to C that are happening at the same time (because the string is vibrating in a very complicated way) and they are what gives that C note it's "quality", in fact they are why the C on your guitar sounds different than the C on a piano or a C on a flute or a C on a clarinet.<SMALL>if one does this, a multitude of ever changing numbers will be the result. according to him, when we think of a string being at a specific frequency, it is really a certain frequency given for a specific window of the strings movement.</SMALL>
When you first pick a note, there's a lot of harmonic content that rapidly "settles down" and leaves the fundamental as the most prominent frequency. If you were going to use a meter like a Fluke and you were looking for middle C, it helps to know that middle C is 261.6hz ahead of time because when you first pick it, there's going to be numberslike 523. and 784. (the 2nd and 3rd harmonics) bouncing around before it settles to 261.6 (the fundamental). On a strobe, the upper bars will be flashing until it settles down to the lowest one.
It's mathematics, which is intertwined with sound and one of the ways to describe the universe.<SMALL>the sacredness of sound, and it turns out the great pyramid is full of things related to sound,</SMALL>