Music & Entertainment

What Is a Guitar Tuner? Learn How to Tune Your Guitar With Instrument Tuners

Written by MasterClass

Mar 28, 2019 • 5 min read

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A good tuner is essential to any professional guitarist or hobbyist who wants excellent intonation on his or her instrument. A guitar that’s even slightly out of tune can derail an otherwise excellent performance, so the best players insist upon accurate, reliable tuners.


What Is a Guitar Tuner?

A guitar tuner is a device that measures the frequencies produced by vibrating strings on either an electric guitar or an acoustic guitar. It then aligns those measurements with notes in a scale. If the frequencies match at particular note, the tuner will display the name of that note on an LED display.

2 Common Types of Guitar Tuners (and How They Work)

There is a wide array of instrument tuners available for today’s players. The two most common types are:

  • Pedal tuner, which receives an audio signal via a 1/4" audio cable and then passes the signal, unchanged, out through another 1/4" cable.
  • Clip-on tuner, which attaches to a guitar’s headstock and measures vibrations in the actual wood of the guitar.

These devices operate in many tuning modes. Perhaps the most common is a chromatic mode, where the tuner will display any pitch on a 12-note chromatic scale. In other modes, the chromatic tuner can be programmed to match the individual string tuning of a standard guitar (EADGBE), popular open tunings (such as DADGAD), or tunings that alter one string (such as Drop D).

Note-By-Note Tuners Versus Polyphonic Tuners

Most tuners work by measuring the frequency of one string at a time. However polyphonic tuners can measure all the string frequencies at once. On these devices, a player will strum all the open guitar strings at once and, using polyphonic tuning, the tuner will identify the pitch of each individual string. This can save valuable time on stage, although some players prefer the precision that comes with tuning one string at a time.

How to Use a Guitar Tuner

A guitar tuner is one of the simplest devices a musician will encounter. To use it:

  1. Turn the tuner on, and pluck a guitar string.
  2. The name of the closest note will appear on the tuner’s screen.
  3. If a string is close to matching a particular note, but somewhat out of tune, the LEDs will indicate whether the note is too low (flat) or too high (sharp).
  4. The LEDs will appear either as solid lights or, if the tuner is in strobe mode, as pulsating lights indicating a direction. (Some tuners also offer a half strobe mode.)
  5. Then, while watching the tuner, the player will adjust the guitar’s tuning pegs until each string reaches its intended pitch.

What’s the Difference Between Guitar Tuners for Electric Versus Acoustic Guitar?

Electric guitar players frequently use pedal tuners, and in most cases, these tuning pedals are connected to a line of other pedals between the guitar and the amplifier. Most tuners are the size of a standard guitar stompbox, but you can find mini tuners that occupy less space.

Some pedal tuners include a mild buffer to boost the level of a guitar’s audio signal, and other such pedals are “true bypass,” which means no such buffer is present. A true bypass tuner may be appropriate if there are very few pedals in a player’s signal chain. But players with a lot of pedals will likely want a tuner with a mild buffer; without such buffers, there will be a noticeable drop in volume by the time the audio signal reaches the amp.

Acoustic guitar players commonly use clip-on tuners, which do not require any audio cables. These clip-ons run on small lithium batteries, and the battery life is typically excellent, lasting many hours. Acoustic players also have the option of using a microphone-based tuner (such as a tuner app on a smartphone), but these tend to be less accurate than clip-ons or tuning pedals, and are typically only used when those more reliable devices aren’t available. And clip-on tuners aren’t just for acoustic guitars. They work on any guitar, and some electric players prefer them to a stompbox pedal.

There are also bass tuners specially made for bass guitars and string basses, but in a pinch, a guitar tuner will often work for both guitars and bass instruments.

Best Guitar Tuners

A good guitar tuner will be accurate, reliable, and will not affect the quality of your guitar’s sound. Many brands fit the bill, but some are more popular than others.

  • Among stompbox guitar pedals, the BOSS TU-3 is often considered the industry standard. It offers many tuning modes and is virtually indestructible. It can also power other pedals in your signal chain if you provide the proper wiring.
  • A popular polyphonic pedal tuner is the TC Electronic PolyTune 3. It allows for speedy tuning of all 6 guitar strings at once, but it can also tune one string at a time.
  • The Korg Pitchblack is a mini stompbox that takes up less real estate on your pedal board.
  • Companies like Digitech and Joyo offer lower priced offerings, and new brands seem to pop up all the time.

There’s an equally wide array of clip-on tuners available. Popular brands include:

  • D’Addario Planet Waves NS Micro
  • Korg PC2 Pitchclip
  • A wide array of offerings from Snark (a particularly accurate model is the ST-8 Super Tight)

How to Tune a Guitar With Your Phone

You can tune your guitar with your phone, but it shouldn’t be the first option. Your phone will rely on its external microphone to pick up the sound of your guitar, and other ambient sounds can interfere with its reading. Still, a tuner app on your phone is quite handy as a backup. BOSS makes one such app, and the Gismart Chromatic Tuner Free is another strong offering. There are hundreds of tuning apps for Android and iOS, so pick the one that suits your personal taste.

A tuner is one of the most important investments a guitar player can make. Whether you’re investing in a $100 stompbox or a $10 clip-on, you want to prioritize excellent intonation to keep your audience and your fellow band members happy. And while free phone apps can be a good backup, made sure you have either a stompbox or clip-on with you at every gig and rehearsal. Even the best players are no match for an out of tune guitar!