Harmonics

[Stephen47]

Is there an article or something that explains harmonics so it is understandable to a person not well versed in it? Some of the stuff I have read makes my hair hurt and it is like reading Greek.
Thanks

[Herb Hunter]

I don't know of an article to suggest but what are some specific questions you have about harmonics?

Do you know how to produce harmonic notes on the guitar?

[robj144]

Harmonics relate to standing waves on a string fixed at both ends which is all math and physics. So to have a solid understanding of them, you need to get understand the physics and math.

However, for most players, a simple understanding is all that is needed: When a string is plucked, many frequencies are produced at the same time. The lowest frequency is the fundamental frequency. For example this could be A at 440 Hz. The other frequencies are simply multiples of this fundamental. So, when an A string is plucked, these frequencies are all produced:

2(440 Hz) = 880 Hz
3(440 Hz) = 1320 Hz
4(440 Hz) = 1760 Hz
5(440 Hz) = 2200 Hz, etc.

Now 880 Hz is an octave higher than the fundamental and 1320/880=3/2, which is a perfect fifth above that A, so that would be a D. This is why sometimes your tuner picks up a the fifth relative to string your playing... in other words detects a D when you pluck an A string. It's also why the D string sometimes vibrates when playing the A string by itself.

The relative loudness (power) of each frequency is different for each instrument and gives each instrument its unique sound or timbre.

Also, the how harmonics interplay between two different notes is also related to dissonance and consonance.

[charles Tauber]

Originally Posted by robj144

Harmonics relate to standing waves on a string fixed at both ends which is all math and physics.

The layman's version is that a single vibrating string can be subdivided into multiple equal-segment vibrating portions. Each portion of the string is separated from the other portions by a point on the string that does not itself vibrate. This point is called a node. Theoretically, a nodes can be created by dividing the original string length in whole-number ratios. A node can be created at 1/2, 1/3, 1/4, 1/5... of the original vibrating string length.

Practically, for string instruments, a node can be created by placing one's finger lightly at a point along the string at any whole-number division of the string's length. For example, if you place your finger at exactly half of the string's length - very near the 12th fret - you divide the string into two equal vibrating portions, separated by the non-vibrating point where your finger touches the string. This is known as the second harmonic.

Dividing the string in 3 equal parts will give you the 3rd harmonic, and so on. With each subsequent division, the length of each segment is shortened - divding a string in 3 parts, each of those three parts is shorter than dividing the same string in 2 parts. The shorter the string, the higher the pitch produced. Each whole-number division produces a known pitch relative to the pitch of the original string length.



While most players aren't aware of this, beyond the second harmonic - a single division of the string at half its length - there are multiple places where the harmonic can be obtained. For example, using the 3rd harmonic, a node can be obtained 1/3 from the nut end of the string - very near the 7th fret - or it can be obtained 1/3 from the bridge end of the string. And so on for dividing the string in 4, 5 ...

[wrench68]

Here's a little more detail.

http://en.wikipedia.org/wiki/Guitar_harmonics

[Knut]

Practical harmonics