Tuning is the first thing you do every time you pick up a guitar, and it is the one skill that affects everything else you play. A guitar that is slightly out does not sound slightly wrong — it sounds muddy and lifeless, because so much of an instrument's warmth comes from strings ringing sympathetically with the ones you actually strike. This guide covers standard tuning and the reference pitches, how to tune by ear with no equipment at all, and how to keep a guitar stable once you have it right. It applies to acoustic, electric and nylon-string guitars alike.

Standard Tuning

Almost every guitar you will encounter is tuned the same way, from the thickest string to the thinnest: E–A–D–G–B–E. Written with octave numbers, that is E2, A2, D3, G3, B3 and E4, spanning two octaves from the low E to the high one.

This is standard across acoustic, electric and classical guitars. The strings differ enormously — steel, nickel-wound, nylon — but the pitches they are tuned to do not.

The frequencies below assume concert pitch of A4 = 440 Hz, which is what tuners default to and what you should use unless you are playing with an ensemble that has agreed otherwise.

Reference Tones

Play each tone and match your string to it. Let the note ring rather than plucking repeatedly — the beating between two close pitches is much easier to hear on a sustained note, and it slows and then disappears as you approach the correct pitch.

Which Way to Turn

Before touching anything, one rule that saves broken strings: always arrive at the pitch from below. If a string is sharp, bring it down well under the note and then come back up to it.

This is not superstition. Tuning up takes the slack out of the string and seats it properly at the nut and the bridge, so it stays where you put it. A string tuned downward into place will creep sharp again as it settles.

Go slowly. Tuning machines are geared, and a quarter-turn moves the pitch a long way. If you find yourself turning and turning with nothing happening, stop and check you are turning the right peg — winding an already-tight string is how strings snap.

Tuning by Ear: The Fifth-Fret Method

Every guitarist should know this, because it works with no equipment at all and it trains your ear in a way that staring at a tuner never will. It tunes the guitar to itself, so the instrument will sound in tune with itself even if the whole thing sits slightly off concert pitch.

Start by getting the 6th string to a reliable E — from the tone above, a piano, or a tuner. Then work across:

1. Press the 6th string at the 5th fret. That is an A. Tune the open 5th string to match it.
2. Press the 5th string at the 5th fret. That is a D. Tune the open 4th string to match.
3. Press the 4th string at the 5th fret. That is a G. Tune the open 3rd string to match.
4. Press the 3rd string at the 4th fret — note the change. That is a B. Tune the open 2nd string to match.
5. Press the 2nd string at the 5th fret. That is an E. Tune the open 1st string to match.

The 4th-fret exception on the 3rd string trips up nearly every beginner. It exists because the interval between the 3rd and 2nd strings is a major third, while every other pair is a fourth — a quirk of standard tuning that makes chord shapes playable at the cost of one irregular step.

Listen for the beating — a slow wavering pulse when two notes are close but not identical. As the pitches converge the pulse slows; when it disappears entirely, the strings are in unison.

Checking with Harmonics

Once the guitar is roughly in tune, harmonics give a more precise check, because they produce pure sustained tones with none of the small errors a fretted note introduces.

Touch the string lightly directly over the 5th fret wire — do not press down — pluck, and lift your finger. You will get a clear bell-like tone. The harmonic at the 5th fret of one string should match the harmonic at the 7th fret of the string below it: 6th string 5th-fret harmonic against 5th string 7th-fret harmonic, and so on up the guitar.

This works for the first four strings. The 3rd-to-2nd pair fails again for the same major-third reason, so check that one against a fretted note or a reference tone.

Nylon-String Guitars

Nylon-string guitars — classical and flamenco instruments — are tuned to exactly the same pitches as any other guitar, but they behave very differently once you get there, and players arriving from steel strings are often alarmed by how much they drift. It is not a fault, and the instrument is not badly made.

Nylon is dramatically more elastic than steel and considerably more sensitive to temperature and humidity. A brand new set will keep going flat for several days as the material stretches and the knots at the tie block settle. Tune, play for a few minutes, tune again, and repeat — over two or three days the strings stabilise and then hold well. You can speed this up by gently lifting each string away from the fretboard along its length and retuning, though be gentler than you would be with steel.

Beyond the first week, expect to retune at the start of every session, and again whenever the guitar moves between a cold room and a warm one. The sensitivity that makes a good classical guitar so responsive is the same sensitivity that makes it react to the weather. Two other differences are worth knowing: nylon strings are tied to the bridge rather than anchored with pins or ball ends, so a slipping knot is a common cause of one string that will not settle — and the plain third string is notoriously the hardest to intonate, which is why several makers now offer a wound third.

Common Problems

• In tune open, sharp up the neck. Usually intonation or string height rather than your tuning — worth having the setup checked.
• One string will not settle. On steel strings, suspect the wraps slipping at the post. On nylon, suspect the knot at the bridge.
• Everything drifts flat overnight. Normal for a new set. If it persists after a fortnight, suspect the anchoring or a tuning machine.
• Chords sound off even when the tuner says all six are right. Old strings are the most common cause — worn windings intonate badly no matter how carefully you tune.
• Tuning shifts when you bend or strum hard. Too many wraps at the post, or a string binding in the nut slot.

Tuners, and When to Ignore Them

A clip-on tuner is the fastest and most reliable route to concert pitch, and there is no virtue in refusing to use one. Set it to A4 = 440 Hz, tune each string upward to the target, then go round a second time, because the neck settles as the total tension changes.

But do not become dependent on it. Tune by ear regularly even when a tuner is sitting right there, because hearing the beating between two close pitches is a genuine musical skill that develops only through use. It is also what lets you fix a guitar mid-performance without looking at a screen.

Quick Reference

1. Tune to A4 = 440 Hz unless told otherwise
2. Strings, low to high: E2 82.41 · A2 110.00 · D3 146.83 · G3 196.00 · B3 246.94 · E4 329.63 Hz
3. Always arrive at the pitch from below
4. By ear: 5th fret across, except the 3rd string, where you use the 4th fret
5. Check with harmonics: 5th fret against 7th fret on the string below
6. Go around all six strings two or three times
7. Expect several days of drift on a new set, especially on nylon

Tuning is worth doing properly rather than approximately. A guitar rewards precision more than most instruments, because its resonance depends on the open strings standing in exact relationships with one another. When they do, notes you did not play ring along with the ones you did — and that is where the sound you bought the guitar for actually comes from.

A guide to tuning a guitar, with reference tones for all six strings