Thirds on the guitar. Consonant or dissonant?


Hello Steve! Tal here,

I have this discussion with piano tuners and various musicians, but when it comes to guitarists it’s a shoulder shrug usually, like it’s just an inherent part of our instrument that the interval of a third is not consistent or usually consonant on the guitar.

So my question is this, intonation, and tuning, (standard set up on a Fender scale, NOT Buzzy Feiten or compensated nut)


Q: how do you personally intonate and then tune, play the guitar so different inversions have relatively event treatment of thirds?


Or am I tripping? Hahahaha

Guitar strings , b, g, d, second inversion triad, C barre chord on the 5th fret, in tune


if I play a root position triad on the same strings, on the eighth fret, I have to pull the G note on the B string sharp with my first finger, even if the guitar is intonated I still have to pull the 5th sharp to be in tune.

Or am I hearing the third incorrectly and it’s supposed to have a more dissonant “beat” pattern against the root and fifth?

Should I tune to the first inversion and not the second as I have been? Is there a fudge with intonation and tuning cents that gets you close?

Have I been perceiving this sound wrong and where would I go to listen and re train my ear? Hahah, I sound like such a nerd.

When I watch and listen to a piano tuner treat thirds it feels like they treat thirds as a more dissonant interval than guitar players do, especially if it’s rock music with basic chords.

Thoughts? Should I chill out and listen to more Miles Davis?

Thank you!!!


Tal, California

One Thought on Thirds on the guitar. Consonant or dissonant?
    19 Aug 2019

    A. I do a fairly unfussy standard 12th fret compensation, the normal routine.

    Then I check and average a few frets in the high register to make sure my vibrato and attack aren’t driving things too sharp.

    Then check a couple of lower frets, 2, 3, 7, to make sure nothing’s badly off, and that’s about it for the guitar.

    What I wind up with is a guitar that intonates flat in the high register if I’m not beating on it. You need the nut cut as low as possible for this if you don’t want the first position too sharp.

    None of that has any effect on the quality of the thirds.

    The mechanical saddle compensation helps correct for action height and string stiffness, but it does so in service of the 12 equal fret spacing.

    If you want to get a Tonic Major triad in tune, you just have to tune that chord shape smooth and then be stuck with it.

    But that’s across the strings, string-to-string, up and down the string the frets are still equal; if you want a better third anywhere else you have to push it flat.

    So, if you go back and read your “how do you?” question again, the short answer is: I don’t.

    You have to make the “third sweetening moves” for chord shapes in the tuning, there’s no way to identically fudge multiple inversions.

    Ok, down in the second paragraph you’re asking about “hearing correctly” regarding the B string in the 5 1 3 inversion also serving as fifth in the root position above.

    Obviously it can’t, because that string needs to be 14 cents flat to make a pure third and 2 cents sharp to make a pure fifth.

    Your options are split the difference or give up.

    The old piano tuning instruction pre-electronic tuning devices was “as much as the ear allows”.

    You don’t need a cent offset, the tuning at this point isn’t a value or a number it’s a compromise you make with your own ear, so go ahead and tighten up on that B string until you can stand the fifth but haven’t quite lost the third.

    Nothing needs to be perfect, just not headed in the wrong direction entirely.

    You’ll spoil the fifth a little to sweeten the third, but somewhere in there you’ll strike an acceptable compromise.

    Plenty more to get into on the subject but I’m gonna call it here until you digest this info.

    Thanks for checking in!