All-fourths tuning

All fourths
The consecutive open notes of all-fourths tuning are spaced apart by five semitones on the chromatic circle, which lists the twelve notes of the octave.
Basic information
Aliases	Perfect-fourths tuning
Interval	Perfect fourth
Semitones	5
Example(s)	E-A-D-G-C-F
Advanced information
Other instruments	Bass guitar
Repetition	No
Advantages	Closely approximates standard tuning
Disadvantages	Difficult to play conventional music
Left-handed tuning	All-fifths tuning
Associated musician
Guitarist	Stanley Jordan Alex Hutchings Tom Quayle
Jazz musician Stanley Jordan stated that all-fourths tuning "simplifies the fingerboard, making it logical".
Regular tunings (semitones)
Trivial (0)
Minor thirds (3)
Major thirds (4)
All fourths (5)
Augmented fourths (6)
New standard (7, 3)
All fifths (7)
Minor sixths (8)
Guitar tunings

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.

Among regular tunings, this all-fourths tuning best approximates the standard tuning.

In all guitar tunings, the higher-octave version of a chord can be found by translating a chord by twelve frets higher along the fretboard. In every regular tuning, for example in all-fourths tuning, chords and intervals can be moved also diagonally. For all-fourths tuning, all twelve major chords (in the first or open positions) are generated by two chords, the open F major chord and the D major chord. The regularity of chord-patterns reduces the number of finger positions that need to be memorized. Jazz musician Stanley Jordan plays guitar in all-fourths tuning; he has stated that all-fourths tuning "simplifies the fingerboard, making it logical".

Among all regular tunings, all-fourths tuning E-A-D-G-C-F is the best approximation of standard tuning, which is more popular. An advantage of standard tuning is that it has many six-string chords, unlike all-fourths tuning. All-fourths tuning is traditionally used for the bass guitar; it is also used for the bajo sexto.

All-fourths tuning is closely related to all-fifths tuning. All-fourths tuning is based on the perfect fourth (five semitones), and all-fifths tuning is based on the perfect fifth (seven semitones). These perfect-fourth and perfect-fifth intervals are termed "inverse" intervals in music theory, and the chords of all-fourth and all-fifths are paired as inverted chords. Consequently, chord charts for all-fifths tunings may be used for left-handed all-fourths tuning.