Compromise Tuning, Or Why Isn't A Guitar Perfectly In Tune Everywh

[bluesy]

In another thread, there was some talk about how a guitar can't be perfectly in tune everywhere across the neck. This seemed to refer to problems, something more than just intonation as set by the bridge saddles. So, say we have set the bridge up so that the octave is perfect, and the frets are all where they should be and properly crowned. I'd like to understand more about how the tuning of a guitar is a compromise.

[fookgub]

It's because the 12-tone equal temperament tuning system is a compromise. Even if your guitar is perfectly set up and intonated, you still have to deal with the inherent problems in 12 tone ET.

There's lots of info about this on the net. Try here and here for a start.

[psw]

There is that...but this applies to most western instrument like the piano...

On the guitar there are other things involved concerned with the actual playing of the instrument that concerns the action and string gauges.

You know for instance that a guitar needs to be intonated by altering the bridge saddles to create slightly longer strings and that these vary with the different string gauges and tensions. In an effort to find an explanation shorter than my prose, the best I could come up with was something longer!

Q: Why in the world would each string have to be a different length? That

doesn't make any sense at all!

A: You're right, it doesn't, and that is why I have absolutely no idea what

the answer to this question is. Someone, please help!

[i believe there are two reasons why the strings must be different lengths.

One, is that the strings must stretch slightly when you push it down to the

fretboard. This stretching increases the tension, and because the strings

are of different gauges, each string is affected a little differently. Also, the

change in tension created be fretting a string may not be the same for each

fret.

The other reason has to do with the stiffness of the strings. When you fret

a string, you are changing the angle of the string where it meets the bridge.

Due to string stiffness, the effective length of the string will be slightly

less than the physical length. The stiffness of the string varies with the

gauge, so each string requires a different amount of compensation. If the

strings were perfectly flexible, the effective length would always equal the

physical length. (Perhaps nylon strings are not as stiff as steel, so that the

individual saddle adjustments are not needed with nylon string guitars) - ed.]

Hmmm...this is from LINK but at least he made an effort and he is on the right track. Most tell you how but not why!

OK..so he is right, as you fret a string, the string is bent, as it is pushed over a fret it is bent more. Open strings of course are not bent at all...

Enter strategies like the earvana nut...this adjusts the scale length at the nut to compensate for this lack of bending effect caused by fretting...amaking the open strings sound a little more "in tune" with the fretted notes. Again, each string requires a slightly different adjustment.

Buzz frietlin's tuning thing moves the nut a little and adjusts the intonation for more of a compromise.

OK...but consider this, regardless of how you play with the nut, all the other frets dissect the strings at right angles...so a lot of the problems concerned with the open strings, also to a lesser extent affect lower fretted notes over higher ones...the b string is a typical culprut. SOme like Yamaha's fretwave thing actually put a little kink in the fret around the b string on the lower frets in order to adjust for this in a manner similar to an intonated nut.

Most of us will have experienced the frustrations of this, particularly on an acoustic guitar (without adjustable intonation or b string compensation) when playing an open e chord perfectly in tune, followed by an open a chord in which the third of the chord, c# on the 2 nd fret b string can sound particularly sour!

There are players strategies to avoid this...tune in a slightly compromised way, avoid these intervals (rock music especially with distortion avoids thirds all together!) avoid open chords or strings.

A very low action and small frets or a very light touch, can really help to make a guitar sound more "in tune"...scolluping may provide some potential to use different finger pressures to adjust for flat notes (though generally the offending notes are irritatingly sharp!)...sitars and traditional lutes have movable frets! I raised the stepboard as an obscure bit of guitar technology that avoided some of the issues with varying pressure, but it is not in itself a solution.

So...at best, the guitar is a compromise.

The whole western tuning system is of course a compromise, but that is something we have become accustomed to and need to play with other instruments in multiple keys...but the guitar has particular "problems" that resists even playing to the equal temperament.

Sometimes this can be pretty obvious, especially if playing with a piano player and using chords with a lot of thirds or full bar chords. As the guitar music progressed and players with more finesse came along, you will notice that the guitar became more of a riff machine, power chord or solo machine or with blues and soul being more of small internals of 2 or maybe three notes...or quick sharp stabs.

You still often here some sour chords in C&W and folk guitar strumming...but even there playing has come along to avoid some of these things by the best players. One common thing is to leave out the thirds and use sus2 chords...this gives a more ambiguous sound to major chords...so an open e to a sus2 (b string open) gives some of the same chord movement without the sour third. (since this is the players corner, I thought I'd add in these kinds of strategies)...

...

I know...I do go on!

But I think it is worth knowing why with intonation, at least so you know a little more about what you are aiming for when you do it...but it is something that players should keep in their mind or their ear when playing music on the guitar...whether the great players are conscious of this technically is unknown (possibly unlikely) but it is reflected in what they tend to or not play and these guitar specific tuning problems have influenced much of the way 'guitar music' has progressed.

Anyway...hope that is of interest

pete

[bluesy]

I know...I do go on!

But I think it is worth knowing why with intonation, at least so you know a little more about what you are aiming for when you do it...but it is something that players should keep in their mind or their ear when playing music on the guitar...whether the great players are conscious of this technically is unknown (possibly unlikely) but it is reflected in what they tend to or not play and these guitar specific tuning problems have influenced much of the way 'guitar music' has progressed.

Anyway...hope that is of interest

pete

Yes, very interesting. Long ago, I developed my own method of tuning a guitar - maybe others use similar methods too, that results in a compromise that works, mostly. Much of what you wrote, explains why it works, sort of

Once the guitar is roughly in tune, I tweak each string to match the high E. I started doing this to avoid the progressive error you get if you use each string to tune the next one up - as advised in many guitar books long ago. First I tune the low E to be exactly one octave below. I tune the B string open, against the high E fretted at the 7th, then check it by fretting the B at the 5th, against the open E. Often a compromise is necessary here if intonation isn't exact. I tune the G string to the high E fretted to the 3rd. Then the D string, fretted the the 2nd, is tuned against the open high E. Lastly the open A string, against the high E fretted to the 5th.

I find the result is a better compromise for the way I play most chords. Except on occasion, and open C chord will sound sour - and this usually means tweaking the G string further - particularly if it's a thin unwound G..

[bluesy]

It's because the 12-tone equal temperament tuning system is a compromise. Even if your guitar is perfectly set up and intonated, you still have to deal with the inherent problems in 12 tone ET.

There's lots of info about this on the net. Try here and here for a start.

Now this is new to me. It's obvious now I read about it.

Thanks for the great links - something for me to read and understand

[psw]

Which is why major thirds always sound weird and people naturally have tried to adjust this by bending the minor third or flattened fifth to sound more "in tune" with blue notes...vocalists too have trouble adjusting to the equal temperament and often sound flat. Personally, I prefer flat to sharp notes in harmony (except with octaves of course)...

I tend to roughly tune the guitar and then tune across strings with various octaves to get a good average. I tend to do this also with the intonation...adjusting the intonation taking into account my medium action, string gauge, touch and typical chord forms that I use. Lately I have been thinking that perhaps I should move towards a much lower action and lighter and less percussive style of playing as I have tended in recent years to play a more self accompliment style that involves a lot more harmony and I am kind of sensitive to this kind of thing.

I have been playing a little more acoustic guitar and I notice it is worse than on my tele say...but when I went away recently I took my old epiphone with a zero fret and found ti to be a whole lot better with open chords and things.

The open C chord can often sound weird...and is a good illustration...the first fret is often stretched quite a bit pushing down the B string just in front of the nut and can sound bad against the perfect 4th between the open G and the C. Unfortunately, raising the G a little only really serves to make the whole chord a little sharp and while F can sound cool and reasonably in tune with it (though the third can sound sharp and sour on some guitars)...the open g chord far less so...solution, avoid the open g chord, or avoid the open c chord...always there are compromises...

You will see there are many who have tried to "fix" this kind of thing with "just temperament" boards...frets at all different scale lengths...but these have some severe musical restrictions...plus bending strings is definitely out!

For a while many years ago, I was attracted to the notion of tuning in all forths...or other symetrical tunings...this is also another strategy and can provide a very interesting and natural fingering patterns...a few players have tried it. Another is that a lot of alternate tunings avoid thirds between strings or tune any thirds more naturally, and this can make them sound a lot sweeter...but then you have to relearn the whole guitar and lose a lot of the tradtional guitar vocabulary...always there are compromises!

pete

[bluesy]

I have been playing a little more acoustic guitar and I notice it is worse than on my tele say...but when I went away recently I took my old epiphone with a zero fret and found ti to be a whole lot better with open chords and things.

I used to have an old Aria acoustic with a bolt-on neck and zero fret. Ahead of it's time (1970s)? Maybe I should use a zero fret on my next build...

The open C chord can often sound weird...and is a good illustration...the first fret is often stretched quite a bit pushing down the B string just in front of the nut and can sound bad against the perfect 4th between the open G and the C. Unfortunately, raising the G a little only really serves to make the whole chord a little sharp and while F can sound cool and reasonably in tune with it (though the third can sound sharp and sour on some guitars)...the open g chord far less so...solution, avoid the open g chord, or avoid the open c chord...always there are compromises...

Wow deja vu Yes that's exactly where I end up! Only this morning I was thinking that I should just avoid that damn open C. I just don't like playing for long periods of time using the 'A' chord shape with a bar chord at the 3rd fret. I guess some chord substitution also helps it not sound so boring as well - open Cmaj7 is cool, and throw in some 6th and 9ths, fit it around the melody and it's done

[psw]

The C chord like this is a neat one for some stuff...

---0---

---0---

---5---

---5---

---3---

---x---

this avoids the open g and give you a close voiced added major 7th and still lots of jangle with the open e third...fretted just a bit higher avoids a lot of the "intonation problems" plus it's a little easier to hold. Don't like the b (major7) in the chord (it can sound a little schmaltzy though not so bad with the minor second of the c in it as well with this chord shape), dampen it with the back of the third finger holding down the g string...

Unfortunately, for some stuff with voice leading and chord melody, that open C is very useful...

I've got lot's of chords like this for all kinds of occasions...some of them to avoid tuning problems, sometimes just to add a kind of open "spice" and others 'cause it's just a little easier!

Another reason that the open C can sound a bit wrong is that in legit harmony, and just generally...you should avoid doubling the third, especially a major third, in a chord...the two e's (dstring and open e) are a problem and can make the out of tune 3rd stand out even more...avoiding that can be a good idea too...

There is something to be said for the zero fret, don't see it so often these days...could make the nut thing a little esier to do also...but perhaps not the best on a guitar with a trem!

[soapbarstrat]

The solution is simple. First, forget about bending strings, then mill T-slots into your fret-board and have special frets that fit into those slots. Then you can move 'em around.

http://www.geigen-und-gitarren-chouard-fre...ret-mobile.html

[psw]

That's interesting...claims the frets are made of plastic in my translation yet wear longer than steel...what kind of plastic would that be do you think?

You have to be really keen though wouldn't you. I know there have been some guitars with removable fretboards held on with magnets I think as well...of course there's always fretless!

[soapbarstrat]

Hmmm. Don't know about the frets being plastic. I could have my wife do as perfect of a translation as could be done, but I tread lightly with that stuff, because I hate when I have to help her translate something from English to German. Boy does she know how to find English words that I really don't know the meaning of (and I even USE some of the words - oh the American way of just taking a word and suddenly giving it a completely different meaning ! )

Anyway, I know that the board has the T slots, and the frets have these added T pieces below the crown, and then there's an O-ring added to make 'em fit in the T-slots more snug. Plus he has them bent in a slight U shape so that if the player pushes the string a little toward either side of the neck, it compensates for that.

[Keegan]

Kunststoff definitely means plastic: http://de.wikipedia.org/wiki/Kunststoff

But there are a lot of plastics that we don't think of as plastic, like Nylon, Kevlar, synthetic rubber, etc. Also, there are a few that are stronger than steel, and tons are if you are talking in terms of strength per unit weight or a specific type of strength like compressive or tensile. Maybe they just mean strength as in resistance to wear from the strings, that would include a lot of plastics.

[joshvegas]

pffft how about this...

[Keegan]

Whoa. That neck is cool. I want one. Maybe the "tone" everyone is searching for is really just a damn neck that plays in tune.

[borge]

equal temperament > true temperament.

unless of course you only play in a couple different keys, which to me is a huge compromise....

[Keegan]

They sell an equal tempered neck, as well as two others, one that's made for "guitar keys" and one that's made for "jazz keys"