Simple Question

harmonics as in when you lightly hold the strings at the 12 fret, pluck and unfret amking a harmonic note? if thats it then what happens in the vibrations from plucking at that position on the string yet not fretting it makes the harmonic. when you unfret it, the vibrations set off either the same strings of another string (Someone can fill it in there... not quite sure... i know on a piano is a different string.) to a certain note. thats the best I can think of right now, cant promis im right though.

Hope I helped
Bstguitarist
KB1LQC

Simple Question, Yes.

Simple Answer, No.

A harmonic in what context?

Mathmaticly? A series of numbers whose recipricals are in arthimetical progression. Example the base of a log.

Acousticly or electricly? (dealing with wave theory) A frequency that is an intrigrial multiple of a fundamental frequency.

Musicly? Notes of a third, fifth, sixth, or octave interval. (A third being three half steps, a fifth, five, a sixth, six and an octave 12.)

Now the musical explanation goes hand and hand with the Acoustic/Electrical definition. It deals with multiples of a root note or fundamental frequency (same thing, different terms for our disscussion) I am more familiar with the wave theroy as it applys to acoustics/electronics than I am of music. Music uses some odd multiples to explane things that are more straight foward in the math involved with wave theory.

Basicly what you have is even multiple harmonics are chordant and pleasing to the ear, odd multiple harmonics are discordant and not pleasing to the ear. However without a bit of discordance sound tends to be bland. Tension and release, discordant and chordant.

When you tune a guitar E A D G B E you have a fifth (chordant) fifth, fifth, fifth, fourth, fifth. The fourth interval G to B gives just enough discordance to make the open chord intresting musicly.

Confused? This is why we need to really study music theroy as well as acoustics to understand what we're doing when we play that F chord and why a guitar isn't a saxaphone.

Acoustically or electrically? (dealing with wave theory) A frequency that is an intregral multiple of a fundamental frequency.

A note, played on an instument, is not a pure note (the signal tone that used to come from radio and TV channels, when no programmes were being broadcast was a pure tone - middle C, if I remember). The first harmonic (or fundamental) is a wave whose length is the same as the entire length of the string - think skipping rope, here. It vibrates at the frequency of that tone, e.g. concert A vibrates 440 times a second.
The second harmonic has a wave exactly half the length of the string. If you think of the skipping rope, again, with someone holding the exact centre of the rope - you get two waves. So you get twice as many vibrations per second.
You can continue this, through all the different harmonics.

As I said, a note, played on a guitar string is not a pure tone - it consists of many different harmonics - which is what gives it it's character. By putting your finger, lightly, on the 12th fret and removing it just as you pluck the string, you effectively remove all the harmonics which don't have nodes on that point (node is the "dead spot" around which the wave vibrates - the places where we had people holding the skipping rope). It also accents the low order harmonic. At the 12th fret, the low order (closest to the fundamental, if you like) harmonic is the 2nd. The 3rd harmonic, if I'm not mistaken, is over the 7th fret.
Musically? Notes of a third, fifth, sixth, or octave interval. (A third being three half steps, a fifth, five, a sixth, six and an octave 12.)

This is a very confusing statement to a musician (I'm going to be one, one day 8) ). An interval is understood to be the distance between two notes of a scale - between A and B or between B and E - and is determined by the number of note names found in the sequence. So, A to B is a second (because of two note names) and B to E is a 4th - B, C, D, E.
When you tune a guitar E A D G B E you have a fifth (chordant) fifth, fifth, fifth, fourth, fifth. The fourth interval G to B gives just enough discordance to make the open chord intresting musicly.

Confused?

Yes, because I understand the intervals between strings to be all 4ths, except G to B, which is a 3rd.

Musicly? Notes of a third, fifth, sixth, or octave interval. (A third being three half steps, a fifth, five, a sixth, six and an octave 12.)

Not quite. From any given starting note you've got several available harmonics:

an octave higher
an octave and a fifth higher
two octaves higher
two octaves and a third higher
two octaves and a fifth higher
two octaves and a bit less than a seventh higher*
three octaves higher*

* - these are pretty difficult to sound

In notation, a harmonic is a note with a 'diamond shaped' head - you get to choose how to finger it. Most octaves are available in more than one place.

Listen to Heart's "Barracuda" - the first lead break is all harmonics (and they're used pretty liberally throughout the tune)

Whoah, I get to correct Tom! This is a rare event and should be noted in the history books of this forum! :lol:

It's actually the second lead break that's in all harmonics! Roger Fisher is a favorite of mine and I actually spoke with him about his days in Heart.

Dang, there must be some type of prize for that! :lol:

Also, from the third post above- isn't a third equivelent to 4 half steps? Or am I lost (Wouldn't be a first). :?

Also, from the third post above- isn't a third equivelent to 4 half steps?

No, it's determined by the number of names in the sequence. Take the C chord, it's made up of stacked thirds - C to E is a third and is 4 semitones, but E to G is also a third and only consists of 3 semitones.

The QUALITY of the interval also plays a part in determining how many semitones make up an interval. So C to E is a major third, whereas C to Eb is a minor third - 3 semitones, but still a third.

Sorry, I forgot to mention that I was thinking major third.

Thanks. 8)

Ok let me see if my basics are off.

I was under the understanding that a fifth was five semitones or five half steps.

I was also understood that each fret on the guitar (or Banjo the other freted instrument I'm familiar with) was one half step or one semi tone.

Then if when starting at second E below C (keyboard) and assending by fifths would tune the A D G strings then a fourth or four semi tones for the B then another fifth for the high E. This gives the pattern of tuning fifth fret, fifth fret, fifth fret, fifth fret, fourth fret, fifth fret.

Or is the theroy program I've been using wrong? If so I need to know so I can buy a better one.

Other than what can be produced by tuning forks, synthisiers and labritory signal generators pure tones are practicly unheard of. All musical instruments produce an infinate number of harmonic tones whe the player strikes a note. Some of those harmonic overtones and undertones are resonate with the body or shape of the instrument. It is those resonate harmonics that give each instrument it's own "voice". Every note on a guitar can be played on a piano but the difference in the resonate harmonics make the guitar sound different than the piano.

This is where the science of acoustics and the physics of wave theroy enter into the mix. The same general rules apply anywhere you have propagating waves. Be it in acoustics (sound) or electronics (radio). Resonate tanks are used in both, wodden bodys in guitars or inductive/capasitive curuits in radios. Filters are used in both, shape of the guitar, or resistive/capasitive curcuits in telivisions.

Ever wonder why nobody builds a solid metal guitar? Other than the fact it would be horribly heavy it would have little to no voice. You would have incredible sustane because there would be very little of the energy put into the string to make it vibrate transfered to the body of the guitar. At the same time there would be very few harmonic tones generated making a very "dull" sounding instrument. I have never heard one of the Yamaha "silent guitars" but I would imagine that they wouldn't be to far from such a therortical instrument. The bench jigs we used in physics to demonstrate vibrational harmonics in the lab never made enough sound to be heard. The string could never overcome the inertia in a 400 pound bench. Or for that mater make the bench resonate.

Whoah, I get to correct Tom!

You know, I saw that, and I figured I remembered the tune wrong.

So I put it on the CD player.

It's the first lead break, starting at 1:12 (the shortest break) that's all harmonics - the second one (after the bridge) doesn't have any at all, and the third, starting at 3:17 is mixed harmonics/fretted notes.

Maybe next time, SirN

:)

Darn! :lol: You are correct. I completely forgot about that first lead break 'cause it's kinda short. So, does this mean I don't get a prize! :lol: :lol: :lol:

I was under the understanding that a fifth was five semitones or five half steps.

When we're not talking about the distilled stuff, a fifth - i.e. fifth interval - will consist of the number of semitones between the notes at either end of the interval.

A fifth in a major scale is 7 semitones:
C D E F G
W W S W = 7 Semitones
1 2 3 4 5

F G A B C (starting at the 4th degree of C)
W W W S = 7 Semitones
1 2 3 4 5

Click here

I'm going to have to find something else for reference material then. I have a theory tutor program that is contraditory to the reference you use. It explanes intervals and harmonic relatonships as being in semitone steps. A fourth as being four semitones, fifth five, ect,

If that's what it says, the theory tutor program is wrong.

Interval measurement comes form notes of a major scale:

2nd - the distance between the root and second note (2 half steps)
3rd - the distance between root and third (4 half steps)
4th - the distance between root and fourth (5 half steps)
5th - the distance between root and fifth (7 half steps)
6th - the distance between root and sixth (9 half steps)
7th - the distance between root and seventh (11 half steps)

but it gets a little more complicated - those are the distances of the major (or perfect, for the 4th and 5th) intervals. Interval measurement is based on the note names rather than fixed half-step distances; if an interval is E-B, that's a perfect fifth, but if it's written E-Cb (the exact same sound) it's a diminished sixth, and if it's written E-Ax (again the same sound) it's a doubly-augmented fourth. These intervals are called enharmonic - they sound the same, but they're different when you look at the notes involved.

You can determine the exact distance of an interval only by knowing the names the notes are called by - to get the number, you simply count the letter steps:

E-F-G-A-B is five letters, so E-B is some kind of fifth.

Then you have to determine what B should be if you're using an E major scale: E-F#-G#-A-B... since it's supposed to be B natural, it's a perfect fifth. If the upper note is in the key of the lower one, it's either perfect (for unison, fourth, fifth, and octave) or major (for anything else).

If it's a half step lower than it should be, the result is diminished (for fourths, fifths, octaves) or minor; a half step larger is augmented for all intervals.

It's evidently wrong then. Looks like the search is on for a better one.