Why Won’t My Guitar Stay in Tune?

Q: About six months ago, I bought a Gibson Hummingbird from the 1990s. Even though it was a little beaten up by the previous owner, it’s a solid guitar. It initially was a little fussy about staying in tune, but lately it’s gotten worse, and it’s particularly frustrating onstage. Why won’t my guitar stay in tune? Do you think I should replace my tuners?

—Jack, Indianapolis

A: This can be a vexing issue! Of course, it’s always worse when this happens in front of an audience. Here are some thoughts about how I would go about weeding out the source of your problem.

Strings

First things first—how are your strings? Old strings can be unreliable, so make sure to change them pretty regularly. And when you do, bear in mind that they’ll need to stretch a bit before you can rely on them to hold tune. You can make that go faster by tuning them up to pitch and pulling upwards a bit on each one a few times. Repeat until the stretch stops flattening the pitch.

Environment

Environmental effects are huge when we talk about guitars staying in tune. Changes in heat and humidity can cause all the wooden parts on your guitar to slightly swell or shrink. It doesn’t take much to affect your guitar. As the wood expands and contracts, the strings are pulled more taut (and made sharp) or let more slack (and made flat). Certain guitars are more sensitive to seasonal changes, and this capriciousness can be much improved with regular setups and by paying attention to your guitar’s humidity needs.

Also in this category, and worth thinking about for anyone who gets up on a stage: Lights are hot! You know how your guitar can be fussy when you bring it in from the cold? Same idea when you get onstage. You may find yourself needing to retune after the first song or two. I find that certain of my guitars are particularly fussy about staying in tune under hot club lights. If possible, put your guitar onstage in a stand for a little while before the show and give it one last tune-up before you start (while your adoring fans are cheering your rock ’n’ roll stage entrance, of course). 

The Nut

Lots of tuning issues start here. Each string should be correctly seated in its slot in the nut. That means that the slot should be the right depth, so that the string isn’t at risk of popping out while you play. It also has to be the right width. If it’s too skinny or if there is a burred edge in it, your string could catch or bind as you tune up, and jump unexpectedly; if this happens you might hear the winds of your string pulling through the nut with a loud “ping.” A well-cut slot with a clean bottom and sides should let the string glide through it freely, and will eliminate a lot of issues.

Here’s a tip: If you’re looking to lubricate your nut slots and you find graphite a messy choice, a little bit of bar soap will do the trick.When you change the strings, just run the soap back and forth over your nut to work a little soap down into each slot. Good, clean fun!

Intonation

Of course, if your guitar isn’t intonated well, it will go increasingly out of tune as you play up the neck. This is a pretty simple fix on an electric guitar with movable saddles, but if you find this on an acoustic with a set saddle, like your modern Hummingbird, see your repair person to talk about your options. Maybe a compensated bone saddle could help, or your entire saddle can be repositioned.

Capo

It’s not unusual to have to retune after putting a capo on your guitar. Some people recommend putting your capo right on top of a fret, but this has always felt a bit precarious to me. The best solution I’ve found is a Shubb-style capo put on from the top side of your neck. You can adjust the tension wheel to put enough “squeeze” in it to hold down your strings without distorting them too much. Of course, when you’re using a capo, a poorly intonated guitar will really bother your ear.

Machines

And least often of all—which is strange, because it’s the first thing that generally occurs to people—we can look to the tuning machines. Check each tuner individually to see if there’s any play when you twist the button. If so, is the play from the button not being screwed onto the post tightly? Is it from a distorted cog? Is the whole machine moving because the screws holding it to the headstock have chewed out their holes? Some tuner issues can be finessed, but if the tuners are too far gone, replacing them will be your best bet.

Another thing to think about is that if you are using a hootenanny strap, the string tied around the base of the headstock can yank on the strings between the nut and the tuner posts.

As a parting note: Some trends in guitar damage only become visible after you’ve looked at lots of guitars. I see more G-string tuners with bent posts than any other string, and pretty often these guitars arrive at the shop in a gigbag. (Screwed-up D-string tuning posts are also pretty common.) Think about it—you put your guitar in the bag and swing it up over your left shoulder and in that motion, it’s pretty easy to misjudge how close you are to a wall, and you can whack that edge of the headstock—or it’s easy to walk into a door jamb. Be careful out there, folks, your guitars will thank you!

Mamie Minch is the co-owner of Brooklyn Lutherie and an active blues player. brooklynlutherie.com

This article originally appeared in the November 2017 issue of Acoustic Guitar magazine.