True Temperament Frets Explained


If you spend any amount of time looking at guitar-related social media content, you’ve probably seen someone using a guitar with squiggly frets. Unlike regular straight frets, these frets wiggle up and down across the fretboard and look quite weird. But why? What’s the point? What’s wrong with regular frets?

In today’s article, we’ll be taking a closer look at true temperament frets, what they do, and why you might consider using them. We’ll also try to keep this as simple as possible and avoid diving too deep into the complex math and physics at play, as there’s a lot of science involved when it comes to temperament and tuning. So pull out a tuner, grab a guitar, and get ready to find out why people are using those weird, squiggly fret guitars. 

The Issue With Normal Guitars

First, let’s talk about normal guitars. Traditional guitars (and other modern fretted string instruments) utilize the equal temperament tuning system. This system divides the octave into 12 equally spaced notes, which is why there are 12 frets (and notes) in an octave.

In the past, various cultures used a system called just intonation. This system divides an octave based on simple mathematical ratios. The result is that things sound more in-tune for the key you tune to, but things sound off in other keys. Over the years, we moved away from just intonation and towards equal temperament due to its ability to sound good in any key. However, equal temperament is also flawed. 

There are natural harmonics when you use strings to create music (like the ones you get at 12th fret). These harmonics are what just intonation tuning systems, like those used by the Greeks, were based on. When you use equal temperament however, you end up slightly moving intervals and causing them to not line up perfectly. This is called tempering. Depending on how you look at it, it either puts everything equally in-tune or equally out of tune.

The result is that certain intervals are never truly in tune as they would be with just intonation. However, you get a tuning system that can be used in any key and nearly any context. The intervals may not sound as perfect, but equal temperament as a more versatile and practical tuning system. It is the best possible compromise possible given the mathematical and physical nature of strings and tuning. 

So what’s all this mean for the guitar? Put simply, it means that your guitar is always going to be a little bit out of tune with something. You’ve likely already noticed this if you’ve been playing guitar for a while, but it’s easy to identify if you haven’t noticed it. Tune your strings so that an open E major chord is perfectly in tune, and then play an open C major chord. You’ll probably notice that the G string is flat. You can also test this by tuning to other open chords, like D major or A major. This is all a result of the equal temperament system and the nature of a guitar’s frets. 

How True Temperament Frets Help

So, how do true temperament frets help with this issue? As you may have guessed, they make slight adjustments for some of these idiosyncrasies with the guitar and the equal temperament system. Keep in mind that this doesn’t shift the guitar to a just tuning instrument; it simply accommodates for some of the “errors” that are fundamental to equal temperament tuning and the guitar. 

The result is a guitar that is perfectly in tune for equal temperament. You can play any chord anywhere on the neck and it will be near perfectly in-tune. Gone are the slight warbles in an open D major chord or a full barre chord up at the 10th fret. This can make the guitar sound more “pure.” Many say that the harmonics sound and feel more rich, and chords without the slight dissonance can sound more pleasing to the ear. 

And to address a few of the common concerns, true temperament frets don’t really impact the feel or play of the guitar. Bends don’t feel any different, and the adjustments on the frets are small enough that they really don’t impact fretting. 

Cons of True Temperament

All that said, true temperament frets aren’t perfect. The biggest downside is cost and practicality. True temperament necks are not cheap, and neither is retrofitting a regular neck. If you’re a stage musician, you’d likely want at least two true temperament guitars so you have a back up. If something happens to your neck on tour, you may have a hard time getting a replacement quickly. And we probably don’t have to tell you what your luthier will say when you ask to get some fretwork done on a true temperament guitar (hint: they won’t be happy). 

The other downside is more of a personal kind of thing, but it is worth noting. Though traditional guitars are imperfect, we have become accustomed to those imperfections. Our ears expect a D major chord to be slightly out of tune. Hearing every chord or interval be perfectly in-tune can just sound wrong to many. 

A good comparison is the Rick and Morty episode where Morty experiences “true level.” In the world, nothing is ever perfectly flat. When he stands somewhere that is perfectly flat, it feels completely different and makes everything else in the world feel slightly off. 

True temperament is similar, as we are used to everything being slightly out of tune. Though you probably won’t suddenly feel like all music is out of tune and that reality is poison like Morty did, true temperament can feel wrong to many who are used to the idiosyncrasies of our standard system. To others, it sounds much better and is a must-have guitar modification. It all depends on your personal preferences and uses. 

A smaller downside to note is that you may notice small tuning differences when playing with non-true temperament instruments. The True Temperament website says this is not an issue, and though it is very minor, there can be some minor warble when playing with other non-true temperament instruments. Keep in mind that these are very minor differences, ones that most people would probably never notice unless they were intently focusing on it. However, it’s still something to keep in mind. 

True Temperament Artists

Let’s take a look at a few artists that utilize true temperament frets in their music. Though most associate true temperament with metal music, that is not necessarily true. 

Steve Vai

Steve Vai was an early adopter of true temperament frets. He recognized the fundamental problem with standard frets and realized that true temperament could help alleviate the issue. His main guitars, Flo and Evo (custom Ibanez JEMs), both had true temperament frets installed for over a decade. Though those guitars no longer have true temperament frets, he still keeps a few true temperament guitars around. 

John McLaughlin 

Jazz legend John McLaughlin also uses a true temperament guitar on occasion. He utilizes a fairly large guitar collection, but he has a Godin with true temperament frets that he uses in the studio and live. As mentioned before, most people associate true temperament with metal, but it can be useful in many different genres. For someone using lots of jazz chords up and down the neck like McLaughlin, true temperament can be a beneficial choice. 

Johannes Möller 

Lastly, Johannes Möller is a great example of true temperament being used on an acoustic guitar. Though he may be less famous than the other guitarists on this list, he’s an incredibly skilled classical guitarist who utilizes true temperament frets. Like the others, he acknowledged the temperament issues inherent to guitar and uses true temperament to alleviate those problems. 

Hear them in action

Paul Davids and Adam Neely made an excellent comparison of true temperament frets with standard frets, check it out here:


The guitar and music as we know it is fundamentally flawed when it comes to temperament. We use equal temperament as a compromise, but it’s not perfect. True temperament can help alleviate those issues by providing more accurate intonation up and down the fretboard. However, true temperament isn’t perfect either. They can be expensive, inconvenient, and present their own issues. 

Still, they can be a great resource for guitarists depending on the music you play and your personal preferences. We recommend trying one out before buying one, whether at a local music shop or from a friend. You may love them or hate them, but they’re worth giving a shot.