Augmented-fourths tuning

Augmented fourths
For every augmented-fourths tuning, the interval between successive open-strings is six semitones, half the circumference of the chromatic circle.
Basic information
Aliases	All-tritone tuning, Diminished-fifth tuning
Interval	Augmented fourth
Semitones	6
Example(s)	C-F♯-c-f♯-c'-f '♯ B-F-b-f-b'-f'
Advanced information
Repetition	After 2 strings
Advantages	Simplified fretboard
Disadvantages	Only two open-string notes
Left-handed tuning	Augmented-fourths tuning
Associated musician
Guitarist	Shawn Lane
Shawn Lane used the B-F-B-F-B-F augmented-fourths tuning for "Tri 7/5" on his The Tri-Tone Fascination.
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 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.

The standard guitar-tuning

interjects exactly one major third amid four perfect fourths for the intervals between its successive open strings. In contrast, the augmented fourths tunings

have only augmented-fourths intervals.

The set of augmented-fourths tunings has three properties that simplify learning by beginners and improvisation by experts: Regular intervals, string repetition, and lefty-righty symmetry. These properties characterize augmented-fourths tunings among non-trivial tunings.

The set of augmented-fourths tunings has three properties that simplify learning by beginners and improvisation by experts: Regular intervals, string repetition, and lefty-righty symmetry.

Besides the set of augmented-fourths tuning, exactly one other set of tunings has these three properties—the trivial class of one-note tunings, which contains the C-C-C-C-C-C tuning, for example.

Augmented-fourths tunings have extended range. Because each of its tritone-intervals between successive strings is wider than the perfect-fourth intervals (and one major third) of standard tuning, augmented-fourths tunings have greater range than standard tuning—six additional notes, only one less note than Robert Fripp's new standard tuning.