All fifths tuningW
All fifths tuning

Among guitar tunings, all-fifths tuning refers to the set of tunings in which each interval between consecutive open strings is a perfect fifth. All-fifths tuning is also called fifths, perfect fifths, or mandoguitar. The conventional "standard tuning" consists of perfect fourths and a single major third between the g and b strings:E-A-d-g-b-e'

All fourths tuningW
All fourths tuning

Among alternative tunings for the guitar, all-fourths tuning is a regular tuning. In contrast, the standard tuning has one irregularity—a major third between the third and second strings—while having perfect fourths between the other successive strings. The standard tuning's irregular major-third is replaced by a perfect fourth in all-fourths tuning, which has the open notes E2-A2-D3-G3-C4-F4.

Augmented-fourths tuningW
Augmented-fourths tuning

Among alternative tunings for guitar, each augmented-fourths tuning is a regular tuning in which the musical intervals between successive open-string notes are each augmented fourths. Because augmented fourths are alternatively called "tritones" ("tri-tones") or "diminished fifths", augmented-fourths tuning is also called tritone tuning or diminished-fifths tuning.

Major thirds tuningW
Major thirds tuning

Among alternative tunings for guitar, a major-thirds tuning is a regular tuning in which each interval between successive open strings is a major third. Other names for major-thirds tuning include major-third tuning, M3 tuning, all-thirds tuning, and augmented tuning. By definition, a major-third interval separates two notes that differ by exactly four semitones.

Regular tuningW
Regular tuning

Among alternative guitar-tunings, regular tunings have equal musical intervals between the paired notes of their successive open strings.

New standard tuningW
New standard tuning

New standard tuning (NST) is an alternative tuning for the guitar that approximates all-fifths tuning. The guitar's strings are assigned the notes C2-G2-D3-A3-E4-G4 ; the five lowest open strings are each tuned to an interval of a perfect fifth {(C,G),(G,D),(D,A),(A,E)}; the two highest strings are a minor third apart (E,G).

Regular tuningW
Regular tuning

Among alternative guitar-tunings, regular tunings have equal musical intervals between the paired notes of their successive open strings.