So I figured out I can tune my G string just a little flat so all the frets sound in tune, except that, of course, leaves open G sounding like F#.

What should I do?

  • With string instruments you can get a situation like this and we say that the string is not true. I see it a lot with tiny Suzuki instruments, and it's because a string made for a much larger instrument was cut down to be much shorter. Extrapolating from that, perhaps a new string would help, or a different brand. Commented Oct 27, 2017 at 4:03
  • Stupid questions: are the 6 strings knotted at the same position on the bridge? I spent 2 days trying to tune a guitar. Everything sounded fine when played open but many chords sounded awful. The strings had different lengths because they were coming from two different bridges. Commented Oct 27, 2017 at 15:46
  • If it's not the intonation or setup then light strings on jumbo frets can do this (or, worse, a scalloped fretboard). If you've got a guitar with big frets it's designed for fast and precise playing - you may just be pushing too hard on the strings. With large frets you're not meant to jam your fingers all the way to the fretboard, just use enough pressure to sound the note. Fretting too hard on large frets will increase the tension in the strings and the notes go sharp.
    – J...
    Commented Oct 27, 2017 at 16:06
  • @EricDuminil What guitar were you playing that had two different bridges?
    – Chad
    Commented Oct 27, 2017 at 19:43
  • @Chad: I don't have any picture. It was an old, cheap, spanish acoustic guitar. It had both a wooden bridge and a metallic floating bridge. Commented Oct 27, 2017 at 19:50

5 Answers 5


Check the intonation. The bridge/saddles may need moving, so that the 12th fret harmonic is exactly the same note as the fretted 12th. As an extra check, capo on 1st fret, and hear the 13th fret harmonic is the same as the fretted 13th.


Look at the nut. The string should make contact with the edge of the nut towards the fretboard. Here is a picture of what it should look like. You can fix it yourself or get it repaired at a luthier/guitar store.

  • 2
    I agree with this answer the most. If all of the frets are producing the correct note on the string, then the intonation is correct. This could very well be an issue with the nut.
    – TyCobb
    Commented Oct 27, 2017 at 20:49

If this is an electric guitar, it could be from using an unwound G. You could try a set of strings with a wound G string and see if that helps.

  • 2
    Unwound G strings are in use on 99% of electrics, which is what they're designed for.
    – Tim
    Commented Oct 27, 2017 at 15:24
  • @Tim I would be surprised if it's really 99%, as many electric sets are sold with wound G strings. If a guitar was set up with such strings then it may very well show intonation problems when using an unwound G (based on how it sits in the nut). Here's a feature from Gibson.com about the subject and the advantages of a wound G: gibson.com/News-Lifestyle/Features/en-us/… Commented Oct 27, 2017 at 19:51
  • @Tim Certainly not not 99%. I never used an unwound G string in my life, and I know plenty of other players who didn't.
    – user207421
    Commented Oct 28, 2017 at 1:25
  • @DarrenRinger- all other things being equal, an unwound G string will play sharper when fretted than a wound one, because it's less elastic. The difference with steel strings is not great, but it's there. Anyone who plays an instrument with wound plus unwound gut or nylon strings can tell you that the lowest unwound string plays much sharper on the frets than the highest wound string, where the difference in elasticity is much greater. Commented Oct 29, 2017 at 20:46

This seems to be a nut/string saddle issue. If you're sure all the fretted notes are in tune when you de tune the third string, then it means that your open G string is too long because the string is not contacting the edge of the nut. The act of fretting the notes is enough to press the string down onto the correct contact point on the nut. You can buy a pocket-sized folding set of mig welder tip cleaning files for a few dollars. Select the appropriate file and ever so gently (think microns here) slope the nut slot so that it falls away on the headstock side. String up and re test after every file stroke: you do not want to take the slot too deep. It's possible that the intonation at the bridge will require a tweak too, depending on how the guitar was 'originally' set up. If your guitar has a bone/plastic saddle do not use the mig tip cleaning files; they should only be used on slots. If your guitar has adjustable saddles remember any adjustment will be tiny.


It is a nut slot issue but not a string hitting too far forward in the slot. It wouldn't matter where the string hits the nut because you are fretting a string and his fretted note is sharp, _ and that I believe is the original posters issue. So -just focusing on the G string here - So saying he gets his G to PERFECT pitch (open) but it's Sharp on the second fret(A) note - or even the first fret( G# )for that matter - this is his complaint I think . This is the most common issue (after you intonate everything of coarse)with guitar sounding out of tune (i.e. playing a Cowboy D). The problem is 2-fold.

  1. It's because the G nut slot needs to be cut a little bit deeper. That eliminates (though ever so small) some of the downward stretch (travel) the string has to make to sound the A note(because the string will be closer to the fret when the nut slot is deeper )so it doesn't travel so far to make the string travel down to A as much (the further the string stretches down the sharper it becomes) It travels down as high as the nut slot-down to the fret.

  2. Add a guitar with taller frets, it exasperates the issue that much. Taller frets even more travel .You have to get that G string slot as close as possible without fretting out and it will solve the issue. Problem is it's hard to get it that close without going TOO far .But it can be done and it will greatly if not fix totally depending on how good a job you do for this issue.

Worked as a guitar tech for Guitar Center and have done this so many times.It's a good idea to have an extra nut in case you do go to far but you can put a gap feeler gauge down on the fret board the exact height of the 1st fret and just take the slot down that far. If you don't have a gage ,in a pinch you could pile layers of duct tape on finger board as high as the 1st. fret but that's not too scientific .

  • And of coarse if all you'er talking about is - (simply that the G string intonates sharp at the 12) , then well yes, you do have to find a way to lengthen the string and moving the saddle back( if you have moveable saddles,AND it's not already all the way back -is the first place to start.But I figure you already know this.
    – Shankk
    Commented Jan 31, 2021 at 19:10

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