What a tuning is
A tuning is the set of notes the open strings of an instrument are set to. It decides which chords fall under the fingers, how far a hand can reach and how the instrument rings. The intervals between the strings matter more than the notes themselves: tune every string of a guitar down a semitone and every shape you know still works, it just sounds lower. Change one interval and the shapes change.
Strings are named from the lowest (thickest) to the highest. The number after a note is its octave: A4 is the A above middle C (C4). Click any string below to hear it, ▶ Hear to hear the whole tuning, or Tune to open the tuner on it.
The reference pitch: A4
Every note is tuned relative to one reference, the A above middle C. Today that is almost always 440 Hz (an international standard since 1955, ISO 16). In equal temperament every semitone is the twelfth root of two (about 1.0595) times the one below, and a semitone is divided into 100 cents, so once A4 is fixed every other note follows: f = A4 × 2(n − 69) / 12 for MIDI note n.
| A4 | Used for | Low E (E2) | vs 440 |
|---|---|---|---|
| 415 Hz | Baroque | 77.72 Hz | -101 cents |
| 432 Hz | Alternative | 80.91 Hz | -32 cents |
| 440 Hz | Standard | 82.41 Hz | – |
| 442 Hz | Orchestral | 82.78 Hz | +8 cents |
| 444 Hz | Bright orchestral | 83.16 Hz | +16 cents |
Many orchestras tune a little higher, to 442 or 443 Hz (some up to 444), for a brighter sound. Early-music groups play Baroque repertoire at 415 Hz, almost exactly a semitone below 440, which is why harpsichords often have a transposing keyboard. 432 Hz has a following that credits it with special properties; there is no evidence for them, but it is a perfectly good choice if you want to sound a third of a semitone low. What matters is that everyone playing together uses the same A. The tuner lets you pick any of these, or type your own.
Guitar
Standard tuning, E A D G B E, has a perfect fourth between neighbouring strings except one major third between G and B. Fourths keep scale shapes compact; the one third makes common chords fit under four fingers. The cost is that every shape shifts by a fret when it crosses the G–B pair. Alternate tunings fall into a few families:
- Lowered: standard shifted down (half step, whole step). Same shapes, lower pitch, slacker strings for easier bends; also suits a singer's range.
- Drop: only the lowest string goes down a tone (Drop D, Drop C). Power chords become one finger, and you gain a low note.
- Open: the open strings form a major chord (Open G, D, E, C). Barre one finger across for any chord: the home of slide guitar.
- Modal: open strings that leave the third out, like DADGAD (a Dsus4), so they ring under both major and minor melodies.
Standard
TuneThe default: fourths between strings, a major third between G and B.
Half step down
TuneStandard shifted down a semitone. Easier bends, darker sound; Hendrix, SRV, Van Halen.
D standard
TuneStandard shifted down a whole tone. Heavy rock and metal.
Drop D
TuneLow E down to D. One-finger power chords and a deeper low end.
Drop C
TuneD standard with the low string dropped another tone.
DADGAD
TuneModal and open-sounding; Celtic and folk fingerstyle.
Open G
TuneStrums a G major chord open. Slide and Keith Richards riffs.
Open D
TuneStrums a D major chord open. Slide and folk.
Open E
TuneStrums an E major chord open. Slide blues.
Open C
TuneWide, resonant open C major.
Bass
The bass is tuned like the four lowest guitar strings an octave down, all in fourths. Five-string basses add a low B; drop and lowered tunings work just like on the guitar. The lowest notes sit around 31–41 Hz, close to the bottom of hearing, which is why a tuner listens more slowly for them.
Standard (4)
TuneAn octave below the guitar's four lowest strings.
Drop D
Tune5-string
TuneAdds a low B below standard.
Half step down
TuneUkulele
The ukulele uses the same intervals as the top four guitar strings, moved up a fourth: G C E A. Its standard tuning is re-entrant: the G string, nearest your chin, is tuned higher than the C next to it, so the strings do not run low to high. That gives the bright, close-voiced strum. Low G tuning swaps in a G an octave lower for a fuller range. The baritone ukulele is tuned exactly like the top four strings of a guitar.
Standard (high G)
TuneRe-entrant: the G string is higher than the C next to it, the 'my dog has fleas' sound.
Low G
TuneLinear tuning with a low G for a fuller range.
D tuning
TuneOld-style, a tone higher than standard.
Baritone
TuneSame as the top four strings of a guitar.
Violin, viola, cello, mandolin
The bowed strings are tuned in perfect fifths, a wider interval than the guitar's fourths: each string covers more notes, and every string pair has the same shape, so fingerings move across the neck unchanged. The violin is G D A E; the viola drops the E and adds a C below (C G D A); the cello is the viola an octave lower. The mandolin borrows the violin tuning, doubled into four pairs of strings, so violin fingerings and fiddle tunes carry straight over.
Standard
TunePerfect fifths.
Standard
TuneA fifth below the violin.
Standard
TuneAn octave below the viola.
Standard
TuneLike the violin, in four pairs of strings.
Banjo
The five-string banjo is usually in open G with a twist: the fifth string is short, starts at the fifth fret, and is tuned to a high G. Played by the thumb, it is a drone that rings through bluegrass rolls. Double C lowers the fourth and second strings for tunes in C.
Tuning tips
- Tune up to the note. If a string is sharp, go below the note and come back up: the gear and string settle and hold better.
- Go round twice after a big change (an open tuning, new strings). The neck bends with the new tension and pulls the first strings out again.
- Pluck, then wait. The first instant of a note is sharp and noisy; read the tuner once the note settles.
- Lower tunings like heavier strings. A tone or more down, thin strings flap and buzz; a heavier set keeps the feel.
- Tune to the band, not to 440, when playing with a piano or an orchestra that uses another A: set the tuner's A4 to match.