Overtone content in guitar design, cause/effect.. Polyphonic solo singing

[vintagelove]

Overtone content in guitar design, cause/effect.. Polyphonic singing


First, if you are unsure of what overtones are, or can't hear them yet, check out a couple videos on YouTube, this is an awesome one someone shared on another forum.

Ok, now it's pretty clear as day the impact of overtones on the sound of an instrument. I'm sure many of us know that already. What I would like to discuss is the cause and effect of overtone content in guitar design.


Why?.... Well, we need something to talk about right... But seriously, I know for myself, having spent a LONG time on 25 and shorter scale lengths (check out the attached article on scale lengths effect on overtone content), whenever I pick up a tele, it is a shock to my ear. There is just so much more going on up there, it's startling for a few seconds (for me at least).


So I'd like to discuss different construction techniques effects on overtone content (as mentioned, scale length is one. How about wood type, dimension, etc)... I'd also like to discuss how these differences impact you as a listener and player. What I hear may be different from others. I'm especially curious to hear from folks who started off as fender players, what do they hear when they play a Gibson???


For me I greatly prefer (what I hear as) the more closely packed together overtones on a Gibson scale, compared to a tele, which to my ear sounds like looking at a rainbow through a telescope, the colors are further spread out. I can see how this could effects someone's playing style (their harmonic choices for instance), as (again this is how I hear it) I like how dissonant chords tend to blend better on shorter scales, all things equal, the more dissonant the chord, the more I prefer it on shorter scales. A cause for the popularity of Gibson by jazz players (let me have it L5 guys!!!)???.... (Is this why L5 guys are L5 guys??) and country (among other harmonically simple music) guys liking Fenders?


Interestingly, I'm also comfortable with the 25" scale sound as I spent thousands of hours playing Carvins. Well recently I've been experimenting with regard to building a dream custom guitar. I want a shorter than traditional scale length. For me, what's perfect is a 25" scale guitar, capo'd at the second fret, tuned to standard pitch at the capo'd note. Would this be a 23" scale length?.... Anyway, I really liked the sound produced by this scale length among other things (feel, tension, stretches, etc). Thoughts???




Excellent article among other things discussing scale lengths effects on overtone content.


Novax Guitars: Information: Technical Lecture

[vintagelove]

Bump

[newsense]

Forget the L5 or the Tele - just give me Anna-Maria !

[Cunamara]

23" scale? Go try a Byrdland and see if you like it. Hmm, Anthony Wilson used one for a long time. ISTR him playing it with Diana Krall in a vid on YouTube.

[marcwhy]

Forget the L5 or the Tele - just give me Anna-Maria !

https://youtube.com/watch?v=UHTF1-IhuC0

Wow, and a lot better looking than those Tibetan monks!

[citizenk74]

Your capo-ed 25" scale sounds pretty close to a Fender Jaguar's scale length, an instrument Joe Pass made some pretty fine music with....

[vintagelove]

Bump, I would appreciate if someone knows what that scale length is could confirm, thanks.

[medblues]

Bump, I would appreciate if someone knows what that scale length is could confirm, thanks.

23.60 inches capoed at first fret
22.27 inches capoed at the second fret


from https://www.stewmac.com/FretCalculator.html

[citizenk74]

So... a tad shorter than the Jaguar's 24" scale. Jags also have that whole cool preset/switching thingamajig goin' on.

I like mine a lot.

[kenbennett]

This is not an easy topic to discuss. First we need some definitions and facts.


Fact 1: All freely vibrating strings produce exactly the same overtones spaced exactly the same "distance" apart.

Definition 1: Distance. Here we mean the normal way of describing the distance between two notes--the interval.

Fact 2: The distance from the fundamental to the first overtone is an octave. From the first overtone to the second, a fifth. Second to third overtone, a fourth. Then a major third. Then a minor third. Then some whole tones, each slightly less than the one before it. Then a couple of two-thirds tones, each getting smaller. Then some semitones, each getting smaller. and on, and on. Our hearing range and sensitivity set a limit on how much of it we can hear.

Fact 3: As seen in Fact 2, the higher up we go in the overtone series, the smaller the interval between them, thus the closer together they are.

Fact 4: The length of the string does nothing to change Fact 1, 2, or 3. [This turns out to be wrong.]

Definition 2: Content. The implication of the OP is that content refers to the relative amplitudes of the various overtones in the harmonic series, not which overtones are produced, because they are all produced. So, harmonic content must mean which overtones are emphasized and which ones are subdued--the balance.

So distance doesn't mean distance; it means interval. And content doesn't mean content; it means the relative loudness of the various overtones.

Different types of strings have different harmonic content. And different picking techniques elicit different harmonic content from the same string.

That takes care of some theory and one aspect of guitar design, the string, two if you count the pick, and you have to count the pick. The rest of the guitar... I'll have to think about it.

Question 1: What would be the design that produced the most harmonics?

Question 2: What is the ideal harmonic content? (If you heard them all, all of the time, it would drive you crazy.)

[pingu]

Question 1: What would be the design that produced the most harmonics?

for a given pitch fundemental I believe the
longer string gives more overtones (brighter timbre)
I believe you can demo this by playing a note , G say , at the first string 3rd fret then that G at the second string 8th fret ,

Question 2: What is the ideal harmonic content? (If you heard them all, all of the time, it would drive you crazy.)

thats one is down to taste , people like different sounds

[kenbennett]

for a given pitch fundemental I believe the
longer string gives more overtones (brighter timbre)
I believe you can demo this by playing a note , G say , at the first string 3rd fret then that G at the second string 8th fret ,

That seems true. Longer scale with its higher tension is brighter, balance of overtones is tilted towards the higher frequencies. But you did move to a different string, thicker. That might be part of the difference there. For scale length itself to be the reason it needs to be the same string gauge tuned to the same pitch for the comparison.

thats one is down to taste , people like different sounds

The ideal amount of overtones, ultimately, yes. I gather that the classical notion of a good violin tone is supposed to respond up to the 7th harmonic. Higher than that, adjacent harmonics are considered too dissonant. Those sounds you leave to the cymbals. Jazz likes a less metallic sound, so my thinking is that jazz players in general want a sound with the very high harmonics similarly, proportionally subdued.

[vintagelove]

If you have not already, be sure to check out the linked article. They did extensive study on the subject. Including developing a mechanical picking device to ensure location and dynamic level.

The results were different scale lengths result in different proportions of harmonic content.

There's obviously no right or wrong, it's subjective. However, I would really like to hear from a person who played a tele for 20 years, what does a Gibson sound like to them? Does it sound like something is missing?


Fwiw, it's hard to find someone who only played one guitar for that long. The reason it probably effects me is that as a lefty, I don't get to play nearly as many guitars as many of you lucky folks..... But I buy a lot of amps to make up for it...

[kenbennett]

I always played Gibsons, but I had a Tele for about 5 years, and I played my own Tele-style design for about 10 years. Now I go back and fourth without thinking about about it. My guitar now is Gibson scale with single coil pickups, rarely turn down the tone knob. I go one string guage up on the shorter scale to maintain the tension. With the bright switch on the Fender amp and the neck pickup it twangs. Nothing missing. Couldn't pull that off with all Gibsons though, many, but not all.

[Vladan]

... For me i greatly prefer ...

... On a gibson scale, compared to a tele, ...

... ... ...

[pingu]

If you have not already, be sure to check out the linked article. They did extensive study on the subject. Including developing a mechanical picking device to ensure location and dynamic level.

The results were different scale lengths result in different proportions of harmonic content.
..

no linked article there

did it corillate ?
longer string=> brighter timbre

[pingu]

For scale length itself to be the reason it needs to be the same string gauge tuned to the same pitch for the comparison.

quite true , I haven't done that experiment
it seems someone has tho

[vintagelove]

no linked article there

did it corillate ?
longer string=> brighter timbre

Hello, check the very bottom of my post, novax guitars.

You should definitely read it, but essentially the longer scale had proportionally more going on up there, but interestingly, there is a bit of a hole in the middle. Again, well worth the read.

best,

[vintagelove]

Yup, that about sums it up. It takes maybe one minute for my ear to adjust.

[targuit]

The issue of overtones and the physics of vibrating strings is fascinating. I also was taken by the video of that woman demonstrating "polyphonic" singing, in part because of a singular experience that happened to me in the town of Perugia in Italy. When I recount this, it is always greeted by understandable skepticism yet as far as I can tell, this was not some sort of hallucination or a dream.

Perugia like many Italian cities often has its sidewalks in the older parts of the city beneath stone or cement arches that create a covered sidewalk to protect pedestrians from rain and snow. And the city is famous for the Umbria Jazz Festival. I happened to be living there for nearly a year overall and attended the jazz festival under the stars on a summer night including performances by Pat Metheny among other jazz musicians. After the Festival I went with a group of friends to someone's house whom I did not know well in an unfamiliar part of town, and when I left I was walking back toward the center of town. It was late and I was singing softly so as not to arouse anyone but enjoying the acoustics of these stone arches and vaulted ceiling over the sidewalk. But at one point I stopped dead in my tracks in wonderment. At that moment I was singing an Jackson Brown tune made famous by the Eagles - Take It Easy. Because I could hear my voice as a three part harmony! This was before the advent of devices that exist today to create harmonies out of a single voice. They were not yet around in the late Seventies. But the three part harmony that was happening had that exactness of tone as the harmonies generated by today's devices.

Of course I was astounded and confounded. I did not move for a few minutes as I tested other tunes with the same result. I tried to decipher the particular architecture of the arches, thinking someone had ingeniously created some kind of space that reflected the sound waves in a particular way, yet this spot looked no different than any other.

Finally, as it was late, I reluctantly left this area and walked back to the center of town and then home. Although I tried to note the location in memory, the next day when I went to try and find the exact spot I failed. And in Italy the streets are not always labeled clearly and I did not have an exact address. I never again found that spot nor has that exact experience happened to me ever again. The memory is distinct, and the only other rational possibility was that it was just a realistic dream or an hallucination of sorts. Yet I remember it as reality.

Although I tried in vain to research acoustics for an explanation, I could not find any discussion of a similar experience. And I had never heard of "polyphonic" singing before this thread. Now I wonder if this paradigm which I find rather amazing in itself could help to explain the singular experience. When I recount this experience I am always aware that it sounds unbelievable but I hope someday to learn the secret of how it happened.

[kenbennett]

targiut, It sounds like you got lucky one night and randomly found a spot where the acoustics of the place emphasized some overtones for you.

The overtones are always there. It's all about which ones are reflected and which ones are absorbed. Then with the ones that are reflected, it's all about which ones are in phase and which ones are out of phase and to what degree they are out of phase. If vibrations that are in phase, their amplitudes add together. Those overtones get louder. Vibrations with different phases subtract. If two have exactly the same frequency and amplitude but opposite polarity (180 degree phase difference), then the result is complete silence. Those overtones disappear.

It's difficult to precisely predict. A telecaster reflects more while other guitars absorb more. That's what this thread is really about. The OP points out the difference between a Fender Telecaster and Gibson guitars in general.

Overtone Singing--the first time I heard of it was in 70s. A friend of mine worked at a Apogee Studios in Atlanta. Kenny Loggins was on tour collecting material for a live album. He booked a couple of days at Apogee to do some editing and overdubbing. Loggins laid down a harmony vocal. Engineer said wow, that sounded like two parts. Kenny Loggins said yea and showed them how he does it. It was simpler than the girl in the video, but essentially the same technique.

[Groyniad]

jim hall tuned his 175 down to get a softer sound didn't he? (and he gets one hell of a distinctive sound)

one of the deep problems i had with fantastic hand-made archtops was that they generated far too much extraneous harmonic content

they had overtones flying off them in all directions (e.g. andersen streamline (17 x 25.4) and i did not like this - i wanted a much stronger 'fundamental' with much less of a noise halo around the note

i think one of the reasons i vastly prefer the L5CES over the L5 wes is that the second pickup destroys a lot of the incidental harmonic accompaniment that i don't really like

[Ioscommuter]

This thread touches on alot of ideas Ive been learning alot about recently. I recently made a switch to lighter gauge strings than I am accustomed to and noticed a change in "tone". While its commonly believed that heavy gauge strings are needed for good tone, I tried a number of things and did some reading on overtones to try to work out how to get the large gauge sounds out of the lighter gauge. While different gauges of strings all have the same series of overtones in the same order, the distinction is really in the proportion. Heavier strings have more of the fundamental and low overtones relative to the amount of higher overtones. Lighter strings are of course quieter but also have less of a drop off in volume as they get into the high partials. This is why as you turn up the volume it still never sounds the same as the heavier gauge. In looking for ways to increase my guitar's lower partials, I came across a magical discovery: My Guitar has a tone knob! I had ignored this for decades, assuming that it could only subtract from my sound and make it muddier. But I turned the tone knob all the way down, then adjusted the amp to where it started to sound good again, (louder, more high end) and then as a last step started to gradually bring the tone control back up, but ended up only having it to 2 or 3, and sounding like i was using much heavier gauge strings. I now feel like I can get better tone out of any gauge string. As a next experiment I plan to try also using a multiband compressor to smooth out the attack of the pick in the high overtones. Would love some feedback on what frequency range that might be.

[kenbennett]

You may find that the attack of the pick and the high overtones go hand in hand. Whatever you do to one may affect the other.

Using a compressor to lessen pick attack may have more to do with attack time than frequency. No matter what frequency you select to compress, you may not be able to subdue the pick sound without a very fast setting on the attack.

[Ioscommuter]

Thanks Ken,
Sorry if the last part of my post was confusing, but I meant frequency. Not so much the sound of the pick touching the strings, but the effect on overtones of the string being picked. In the first instant of being picked the upper partials are much more pronounced. I believe that for a thinner string where the upper harmonics are relatively louder anyway, this effect would be stronger. If I compress just these upper harmonics (as they sound their loudest at the moment of picking) in addition to the general eq changes, I am assuming it would help achieve the more mellow effect of heavier strings. There would end up being a time factor to when this is happening of course, probably just in the first second or fraction thereof after plucking, but I think it would be based off of when these partials are above a certain volume and not necessarily require a time based effect. Also I could be wrong about this part being necesarry, and maybe just the eq that I am already doing would cover the plucking harmonics anyway. I'll probably just need to try it and see.