Communities of guitarists who share a common musical tradition often use the same or similar tuning styles.

In scientific pitch notation,[4] the guitar's standard tuning consists of the following notes: E2–A2–D3–G3–B3–E4 .

This is to reduce the need for ledger lines in music written for the instrument, and thus simplify the reading of notes when playing the guitar.

[3] When barring each fret in standard tuning, only and all of the notes of pentatonic scales are produced.

These offer different kinds of deep or ringing sounds, chord voicings, and fingerings on the guitar.

The drop D tuning is common in electric guitar and heavy metal music.

This creates an "open power chord" (three-note fifth) with the low three strings (DAD).

Although the drop D tuning was introduced and developed by blues and classical guitarists, it is well known from its usage in contemporary heavy metal and hard rock bands.

Early hard rock songs tuned in drop D include the Beatles' "Dear Prudence" (1968) and Led Zeppelin's "Moby Dick" (1969).

In the mid-1980s, three alternative rock bands, King's X, Soundgarden and Melvins, influenced by Led Zeppelin and Black Sabbath, made extensive use of drop D tuning.

This new technique of playing power chords introduced by these early grunge bands was a great influence on many artists, such as Rage Against the Machine and Tool.

The open G tuning variant G–G–D–G–B–D was used by Joni Mitchell for "Electricity", "For the Roses" and "Hunter (The Good Samaritan)".

[36] Truncating this tuning to G–D–G–B–D for his five-string guitar, Keith Richards uses this overtones-tuning on the Rolling Stones's "Honky Tonk Women", "Brown Sugar" and "Start Me Up".

[37] The seven-string Russian guitar uses the open G tuning D–G–B–D–G–B–D, which contains mostly major and minor thirds.

[40] By contrast, it is more difficult to fret a minor chord using an open major-chord tuning.

Bukka White and Skip James[41] are well known for using cross-note E-minor (E B E G B E) in their music, as in 'Hard Time Killin Floor Blues'.

C6, E6, E7, E6/9 and other such tunings are common among lap-steel players such as Hawaiian slack-key guitarists and country guitarists, and are also sometimes applied to the regular guitar by bottleneck (a slide repurposed from a glass bottle) players striving to emulate these styles.

The strings may be tuned to exclusively present a single interval (all fourths; all fifths; etc.)

This makes the strings easier to bend when playing and with standard fingering results in a lower key.

[43] Grunge band Nirvana also used this tuning extensively throughout their career, most significantly in their albums Bleach and In Utero.

It is used mostly by heavy metal bands to achieve a heavier, deeper sound, and by blues guitarists, who use it to accommodate string bending and by 12-string guitar players to reduce the mechanical load on their instrument.

Metal band Megadeth has also been using this tuning since their album Dystopia to facilitate frontman Dave Mustaine's age and voice after his battle with throat cancer.

There are separate chord-forms for chords having their root note on the third, fourth, fifth, and sixth strings.

In contrast, regular tunings have equal intervals between the strings,[45] and so they have symmetrical scales all along the fretboard.

[48] Beginning players first learn open chords belonging to the major keys C, G, and D. Guitarists who play mainly open chords in these three major-keys and their relative minor-keys (Am, Em, Bm) may prefer standard tuning over many regular tunings,[49][50] On the other hand, minor-thirds tuning features many barre chords with repeated notes,[51] properties that appeal to acoustic-guitarists and beginners.

Regular tunings that are based on either major thirds or perfect fourths are used, for example, in jazz.

[52][53] Jazz musician Stanley Jordan stated that all-fourths tuning "simplifies the fingerboard, making it logical".

In contrast, inverting triads in standard and all-fourths tuning requires three fingers on a span of four frets.

[61] In standard tuning, the shape of an inversion depends on the involvement of the major-third between the 2nd and 3rd strings.

[a] Some closely voiced jazz chords become impractical in NST and all-fifths tuning.