Standard guitar tuning, explained (and why it's E A D G B E)

The six strings of a guitar in standard tuning are E A D G B E, low to high. There are good reasons for that specific arrangement — and for the seemingly random "B" that breaks the pattern.

The pattern: fourths, except one third

Five of the six string intervals in standard tuning are perfect fourths (5 semitones apart): E to A, A to D, D to G, B to high E. The exception is the interval between the G string and the B string, which is a major third (4 semitones).

Why the inconsistency? The "all fourths" tuning would have made the high strings B and E (instead of B and E with G shifted). That tuning exists — it's called fourths tuning — and some bassists and jazz guitarists use a version of it. But standard tuning's compromise has a specific advantage: it makes chord shapes playable across the entire fretboard.

If you tuned all in fourths, basic open chords (C, G, D, A) would require uncomfortable stretches with your fretting hand. The major-third interval between G and B compresses the high end of the guitar enough to make these shapes physically reachable. It's a trade-off: slightly inconsistent string-to-string intervals, in exchange for ergonomic chord voicings.

Why these specific notes (and not, say, F♯ B E A C♯ F♯)?

The guitar's tuning predates the modern A=440 Hz standard. Throughout history, guitars were tuned to whatever pitch happened to be the local convention — often based on choir or organ pitch.

The choice of E as the lowest note has a few practical drivers:

• E2 (82.4 Hz) sits comfortably in the bass register without being so low that nylon or steel strings of typical thickness become flabby.
• Going lower (D, C, B) requires either thicker strings or longer scale lengths to maintain tension and clarity.
• E is the note most natural for the human ear to perceive as a "root" in early Western music — many folk songs and early rock tunes are in E or A for this reason.

The high E (E4, 329.6 Hz) is dictated by the same logic in reverse: thinner strings can go higher than this, but the ergonomics of the typical guitar scale (24.75" to 25.5") make E a comfortable upper limit before strings start feeling tight and harsh.

What "in tune" actually means

Each string in standard tuning is tuned to a specific frequency, calculated from the concert A reference. With A=440 Hz:

• Low E (6th string, E2): 82.41 Hz
• A (5th string, A2): 110.00 Hz
• D (4th string, D3): 146.83 Hz
• G (3rd string, G3): 196.00 Hz
• B (2nd string, B3): 246.94 Hz
• High E (1st string, E4): 329.63 Hz

You can use a chromatic tuner with any reference pitch (the standard is 440, but 432, 442, and Baroque 415 are also options) to tune to these notes. The tuner listens to your microphone, identifies which note you're playing, and tells you whether you're flat or sharp by how many cents (one cent = one hundredth of a half-step).

Common alternate tunings

Standard tuning isn't sacred — countless songs use alternate tunings to enable easier chord shapes, lower bass notes, or unusual voicings. The most common alternates:

Drop D (DADGBE): low E lowered to D. Makes power chords on the bottom three strings playable with a single barre, and adds a deeper bass note. Used in: a huge swath of rock and metal, plus folk and singer-songwriter material.

Half-step down (E♭A♭D♭G♭B♭E♭): every string lowered a half-step. Singers often request this to lower the song's key by a semitone without changing chord shapes. Famous in Hendrix-era recordings and a lot of blues.

Open G (DGDGBD): the open strings form a G major chord. Used heavily by Keith Richards and in slide guitar.

Open D (DADF♯AD): the open strings form a D major chord. Common in slide and folk.

DADGAD: a Celtic and acoustic-fingerstyle favorite. The strings don't form a clear major or minor chord, which gives DADGAD its distinctive open, modal sound.

Tuning by ear (the old-school method)

If you don't have a tuner, you can tune the guitar to itself starting from any reference pitch. The traditional method:

1. Tune the low E to a reference (a piano, another guitar, or the tone generator at 82.41 Hz).
2. Hold down the 5th fret of the low E — that's an A. Tune the open A string (5th string) to match.
3. Hold down the 5th fret of the A string — that's a D. Tune the open D string to match.
4. Hold down the 5th fret of the D string — that's a G. Tune the open G string to match.
5. Hold down the 4th fret of the G string (because of the third interval) — that's a B. Tune the open B string to match.
6. Hold down the 5th fret of the B string — that's an E. Tune the open high E string to match.

This method works in any environment and doesn't require any equipment, but it's slower and slightly less accurate than a chromatic tuner — small errors accumulate as you move through the strings.

Why your guitar keeps going out of tune

Even after a perfect tuning, guitars drift. Common causes:

• Temperature and humidity changes: wood expands and contracts, changing string tension.
• New strings: they stretch for the first day or two of play before settling.
• Aggressive bending or playing: physical movement of the strings shifts their tension at the nut and bridge.
• String slippage at the tuning pegs: if strings aren't wound on the pegs cleanly, they can slip under tension.
• Worn nut slots: if the nut grooves are too tight, strings get hung up and the tuning becomes unstable.

A well-set-up guitar with fresh strings should hold tune for hours. Most professional players retune between every song or two during a performance — partly to compensate for the natural drift, partly because audiences notice even small tuning issues.