Official Luthiers Forum!

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

the wikipedia article is not bad, here are a couple more:

http://cnx.org/content/m11118/latest/
http://www.music.sc.edu/fs/bain/atmi02/ ... audio.html

basically (quite basically, actually) all sounds are made of a series of different frequencies, which are referred to as partials. these blend to form the sound you hear and are what confers the sound its timbre. in the case of periodic sounds (which have a distinct pitch - a guitar note, a whistle, ...) the lower frequency is called the fundamental and the rest of the frequencies - which are (theoretically at least) integer multiples of it - are called harmonics. these can also be called overtones. in the case where the upper partials are not related to the lower frequency (say, a cymbal crash or a door slam) , these are still called overtones, but not harmonics. so the term harmonic is reserved for an integer multiple of the fundamental frequency of a sound. at least this is my impression of it.

cheers,
miguel.

_________________
member of the guild of professional dilettantes

Further info...

'Harmonics' on strings are heard when you touch the string at a point that's some integer fraction of the length, such as 1/2, 1/3, 1/4, and so on. This supresses a lot of the vibrations of the string, and effectively divides it into sections. Each of the these sections acts just like a new string that is a fraction of the length of the original. Thus, touching the string halfway along, at the 12th fret, divides it into two sections that each vibrates at twice the frequency of the whole string, which is the same effect you get by fretting the string at the 12th fret: you hear a tone that's an octave higher (more or less).

I put ellipses around 'harmonic' because, by definition, a harmonic is an exact multiple of the fundamental frequency, and you don't usually get that on strings. This is mostly due to the stiffness of the string itself, which raises the pitch of the upper partials (the general name for this sort of thing) so that they're no longer 'harmonic'. They're close, though, on good strings.

I don't blame you if your hair hurts: there's a lot to this stuff, and it takes a while to get your head around it. It's worth doing, though.

Not from a guitar perspective, but here are the very basics.

http://www.physicsclassroom.com/Class/waves/u10l4d.cfm

Mike

_________________
Mike Lindstrom