{{Short description|Set of alternative guitar tunings}} {{about|alternative tunings of the guitar to which the term "regular" is applied|regular tunings of musical scales in general|Regular temperament}} {{Use dmy dates|date=July 2024}} {{Infobox Regular tuning | regular_tuning_name = Regular tunings |image_top =Pitch class space.svg |caption_top=For regular guitar-tunings, the distance between consecutive open-strings is a constant musical-interval, measured by semitones on the chromatic circle. The chromatic circle lists the twelve notes of the octave. |other_names = Uniform tunings<br />All-interval tunings |interval= |semitones = |examples = |advanced = TRUE |repetition = |other_instruments = |advantages = Provides new material for improvisation by advanced guitarists |disadvantages = Makes it difficult to play music written for standard tuning. |lefty = |guitarist = |guitarist_image= |guitarist_alt= |guitarist_caption= }}

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

''Guitar&nbsp;tunings'' assign pitches to the open&nbsp;strings of guitars. Tunings can be described by the particular pitches that are denoted by notes in Western music. By convention, the notes are ordered from lowest to highest. The ''standard tuning'' defines the string pitches as E, A, D, G, B, and E. Between the open-strings of the standard tuning are three perfect-fourths (E–A, A–D, D–G), then the major third G–B, and the fourth perfect-fourth B–E.

In contrast, regular tunings have constant intervals between their successive open-strings: * 3 semitones (minor third): Minor-thirds, or ''Diminished'' tuning * 4 semitones (major third): Major-thirds or ''Augmented'' tuning, * 5 semitones (perfect fourth): All-fourths tuning, * 6 semitones (augmented fourth, tritone, or diminished fifth): Augmented-fourths tuning, * 7 semitones (perfect fifth): All-fifths tuning

For the regular tunings, chords may be moved ''diagonally'' around the fretboard, as well as ''vertically'' for the repetitive regular tunings (minor thirds, major thirds, and augmented fourths). Regular tunings thus often appeal to new guitarists and also to jazz-guitarists, as they facilitate key transpositions without requiring a completely new set of fingerings for the new key. On the other hand, some conventional major/minor system chords are easier to play in standard tuning than in regular tuning.<ref name="Regular"><!-- This refers to the 2001 chapter, not the 2010 pdf file of the whole guide, or the 2011 webpage. Please do NOT remove merge this with the 2011 reference! -->{{harvtxt|Sethares|2001}}</ref> Left-handed guitarists may use the chord charts from one class of regular tunings for its left-handed tuning; for example, the chord charts for all-fifths tuning may be used for guitars strung with left-handed all-fourths tuning.

The class of regular tunings has been named and described by Professor William Sethares. Sethares's 2001 chapter ''Regular tunings'' (in his revised 2010–2011 ''Alternate&nbsp;tuning guide'') is the leading source for this article.<ref name="Regular"/> This article's descriptions of particular regular-tunings use other sources also.

==Standard and alternative guitar-tunings: A review== {{Tall image|Standard diagonal shifting of C major chord.png|200|600|In standard tuning, the C-major chord has three shapes because of the irregular major-third between the G- and B-strings.|right}} This summary of standard tuning also introduces the terms for discussing alternative tunings.

===Standard=== <score sound="1"> { \clef "treble_8" \time 6/4 < e, a, d g b e' >1. e,4 a, d g b e' < e, a, d g b e' >1.} </score> {{Main|Standard guitar-tuning}}

Standard tuning has the following open-string notes: :E2–A2–D3–G3–B3–E4. In standard tuning, the separation of the second (B), and third (G) string is by a major-third interval, which has a width of four semitones.

{| class="wikitable" ! Standard tuning !! open !! 1st fret (index) !! 2nd fret (middle) !! 3rd fret (ring) !! 4th fret (little) |- | 1st string ! E4 || F4 || F{{Music|♯}}4/G{{Music|♭}}4|| G4 || G{{Music|♯}}4/A{{Music|♭}}4 |- | 2nd string ! B3 | C4 || C{{Music|♯}}4/D{{Music|♭}}4|| D4 || D{{Music|♯}}4/E{{Music|♭}}4 |- | 3rd string ! G3 | G{{Music|♯}}3/A{{Music|♭}}3|| A3 || A{{Music|♯}}3/B{{Music|♭}}3 || B3 |- | 4th string ! D3 | D{{Music|♯}}3/E{{Music|♭}}3|| E3 || F3 || F{{Music|♯}}3/G{{Music|♭}}3 |- | 5th string ! A2 | A{{Music|♯}}2/B{{Music|♭}}2|| B2 || C3 || C{{Music|♯}}3/D{{Music|♭}}3 |- | 6th string ! E2 | F2 || F{{Music|♯}}2/G{{Music|♭}}2|| G2 || G{{Music|♯}}2/A{{Music|♭}}2 |- | align="center" colspan="6" | ''Chromatic note progression'' |} The irregularity has a price. Chords cannot be shifted around the fretboard in the standard tuning E–A–D–G–B–E, which requires four chord-shapes for the major chords. There are separate chord-forms for chords having their root note on the third, fourth, fifth, and sixth strings.<ref>{{harvtxt|Denyer|1992|p=119}}</ref>

=== Alternative === {{Main|Alternative guitar-tunings}}

''Alternative ("alternate")'' tuning refers to any open-string note-arrangement other than standard tuning. Such alternative tuning arrangements offer different chord voicing and sonorities. Alternative tunings necessarily change the chord shapes associated with standard tuning, which eases the playing of some, often "non-standard", chords at the cost of increasing the difficulty of some traditionally-voiced chords. As with other scordatura tuning, regular tunings may require re-stringing the guitar with different string gauges. For example, all-fifths tuning has been difficult to implement on conventional guitars, due to the extreme high pitch required from the top string. Even a common approximation to all-fifths tuning, new standard tuning, requires a special set of strings.

==Properties== left|thumb|alt=A fretboard with line-segments connecting the successive open-string notes of the standard tuning|In the ''standard'' guitar-tuning, one major-third interval is interjected amid four perfect-fourth intervals. In each ''regular'' tuning, all string successions have the same interval. {{Tall image|Diagonal shift of C-major chord in major-thirds tuning.png|200|350|alt=A C major chord in four positions.|Chords can be shifted diagonally in regular tunings, such as major-thirds (M3) tuning.|right}} thumb|In regular tunings like M3 tuning, chords maintain the same shape, unlike the chords of standard tuning. right|thumb|300px|alt=The fretboard of major-thirds tuning is segmented into four-fret intervals, frets 0–3, 4–7, and 8–11; the natural notes are labeled.|The fretboard of major-thirds tuning is segmented into four-fret intervals, which simplifies its learning and also reduces the need for shifting the left hand. {{See also|Interval (music)}}

With standard tuning, and with all tunings, chord patterns can be moved twelve frets down, where the notes repeat in a higher octave.

For the standard tuning, there is exactly one interval of a third between the second and third strings, and all the other intervals are fourths. Working around the irregular third of standard tuning, guitarists have to memorize chord-patterns for at least three regions: The first four strings tuned in perfect fourths; two or more fourths and the third; and one or more initial fourths, the third, and the last fourth.

In contrast, regular tunings have constant intervals between their successive open-strings. In fact, the class of each regular tuning is characterized by its musical interval as shown by the following list: * 3 semitones (minor third): Minor-thirds tuning, * 4 semitones (major third): Major-thirds tuning, * 5 semitones (perfect fourth): All-fourths tuning, * 6 semitones (augmented fourth, tritone, or diminished fifth): Augmented-fourths tuning, * 7 semitones (perfect fifth): All-fifths tuning

The regular tunings whose number of semitones ''s'' divides 12 (the number of notes in the octave) repeat their open-string notes (raised one octave) after 12/''s'' strings: For example, * having three semitones in its interval, minor-thirds tuning repeats its open notes after four (12/3) strings; * having four semitones in its interval, major-thirds tuning repeats its open notes after three (12/4) strings; * having six semitones in its interval, augmented-fourths tuning repeats its notes after two (12/6) strings.

Regular tunings have symmetrical scales all along the fretboard. This makes it simpler to translate chords into new keys. For the regular tunings, chords may be moved diagonally around the fretboard.

The shifting of chords is especially simple for the regular tunings that repeat their open strings, in which case chords can be moved vertically: Chords can be moved three strings up (or down) in major-thirds tuning,<ref name="Griewank3">{{harvtxt|Griewank|2010|p=3}}</ref> and chords can be moved two strings up (or down) in augmented-fourths tuning. Regular tunings thus appeal to new guitarists and also to jazz-guitarists, whose improvisation is simplified by regular intervals.

===Particular conventional chords are more difficult to play=== On the other hand, particular traditional chords may be more difficult to play in a regular tuning than in standard tuning. It can be difficult to play conventional chords especially in augmented-fourths tuning and all-fifths tuning,<ref name="Regular"/> in which the wide (tritone and perfect-fifth) intervals require hand stretching. Some chords that are conventional in folk music are difficult to play even in all-fourths and major-thirds tunings, which do not require more hand-stretching than standard tuning.<ref name="Patt"/> On the other hand, minor-thirds tuning features many barre chords with repeated notes,<ref name=Sethares5455>{{harvtxt|Sethares|2001|pp=54–55}}</ref> properties that appeal to beginners.

===Frets covered by the hand===

The chromatic scale climbs from one string to the next after a number of frets that is specific to each regular tuning. The chromatic scale climbs after exactly four frets in major-thirds tuning, so reducing the extensions of the little and index fingers ("hand stretching").<ref>{{harvtxt|Griewank|2010|p=9}}</ref> For other regular tunings, the successive strings have intervals that are minor&nbsp;thirds, perfect&nbsp;fourths, augmented&nbsp;fourths, or perfect&nbsp;fifths; thus, the fretting hand covers three, five, six, or seven frets respectively to play a chromatic scale. (Of course, the lowest chromatic-scale uses the open strings and so requires one less fret to be covered.)

{{clear}}

==Examples== right|thumb|Every minor-thirds tuning repeats its open notes after four strings.

The following regular tunings are discussed by Sethares, who also mentions other regular tunings that are difficult to play or have had little musical interest, to date.

===Minor thirds=== <!--Minor thirds tuning redirects directly here. Please do not link minor-thirds tuning in the text, which just would create a useless redirection here. -->

:C2–E{{music|b}}2–G{{music|b}}2–A2–C3–E{{music|b}}3,<ref name="Sethares54"/><ref>{{cite web | url=http://www.gtdb.org/tuner/acd-sharp-f-sharp-ac/ | title= ACD#F#AC: Minor thirds (m3)| publisher=Guitar tunings database | date=3 February 2013 | access-date=4 February 2013}}</ref> or :B2–D3–F3–A{{music|b}}3–B3–D4<ref>{{cite web | url=http://www.gtdb.org/tuner/g-sharp-bdfg-sharp-b/ | title=G#BDFG#B: Minor thirds (m3) | publisher=Guitar tunings database | date=3 February 2013 | access-date=4 February 2013}}</ref>

In each minor-thirds (m3) tuning, every interval between successive strings is a minor third. Thus each repeats its open-notes after four strings. In the minor-thirds tuning beginning with C, the open strings contain the notes (C, E{{music|b}}, Gb) of the diminished&nbsp;C triad.<ref name="Sethares54">{{harvtxt|Sethares|2001|pp=54}}</ref>

Minor-thirds tuning features many barre chords with repeated notes,<ref name="Sethares5455" /> properties that appeal to acoustic guitarists and to beginners. Doubled notes have different sounds because of differing "string widths, tensions and tunings, and [they<!-- the doubled notes -->] reinforce each other, like the doubled strings of a twelve string guitar add chorusing and depth," according to William&nbsp;Sethares.<ref name="Sethares54"/>

Achieving the same range as a standard-tuned guitar using minor-thirds tuning would require a nine-string guitar (e.g. E{{music|b}}2–G{{music|b}}2–A2–C3–E{{music|b}}3–G{{music|b}}3–A3–C4–E{{music|b}}4). {{clear}}

===Major thirds=== right|thumb|The major-thirds tuning A{{music|b}}2–C3–E3–A{{music|b}}3–C4–E5 repeats its three open-notes in the higher octave after three strings. {{multiple image | total_width =400 | footer = Major-thirds tuning repeats its notes after three strings. | image1 = Shift C-major chord three strings in major thirds tuning on six-string guitar.png | alt1 = The C major chord (C, E, G) on the bass (4-6) and tenor (1-3) strings of M3 tuning, on frets. The C note and the E note have been raised 3 strings on the same fret. | caption1 =Chords vertically shift. | image2 =First and second inversions of C-major chord on six-string guitar with major-thirds tuning.png | alt2 =The C major chord and its first and second inversions. In the first inversion, the C note has been raised 3 strings on the same fret. In the second inversion, both the C note and the E note have been raised 3 strings on the same fret. | caption2 =In major-thirds tuning, chords are inverted by raising notes by three strings on the same frets. The inversions of a C major chord are shown.<ref name="KirkebyMajor">{{harvtxt|Kirkeby|2012|loc=[http://v3p0.m3guitar.com/html/fretmaps_chords_major.html "Fretmaps, major chords: Major Triads"]}}</ref> }} {{Main|Major-thirds tuning}}

<score sound="1"> { \clef "treble_8" \time 6/4 < c, e, aes, c e aes c' e' aes' >1. || < c, e, aes, >2 <c,>4 <e,>4 <aes, >4 < c, e, aes, >4 || < c e aes >2 <c >4 <e >4 <aes >4 < c e aes >4 || <c' e' aes' >2 <c' >4 <e' >4 <aes' >4 < c' e' aes' >4 || <c, e, aes, c e aes c' e' aes'>1. } </score>

''Major-thirds tuning'' is a regular tuning in which the musical&nbsp;intervals between successive strings are each major thirds.<ref name="Sethares56">{{harvtxt|Sethares|2001|pp=56}}</ref><ref name="Griewank">{{harvtxt|Griewank|2010}}</ref> Like minor-thirds tuning (and unlike all-fourths and all-fifths tuning), major-thirds tuning is a repetitive tuning; it repeats its octave after three strings, which again simplifies the learning of chords and improvisation;<ref name="Kirkeby">{{cite web|first=Ole|last=Kirkeby|date=1 March 2012|title=Major&nbsp;thirds tuning|access-date=10 June 2012 |url=http://v3p0.m3guitar.com/|publisher=m3guitar.com|id=cited by {{harvtxt|Sethares|2012}} and {{harvtxt|Griewank|2010|p=1}}|url-status=dead|archive-url=https://web.archive.org/web/20150411064851/http://v3p0.m3guitar.com/|archive-date=11 April 2015}}</ref> similarly, minor-thirds tuning repeats itself after four strings while augmented-fourths tuning repeats itself after two strings.

Neighboring the standard tuning is the all-thirds tuning that has the open strings :E2–G{{music|#}}2–B{{music|#}}2–E3–G{{music|#}}3–B{{music|#}}3 (or F{{music|b}}2–A{{music|b}}2–C3–F{{music|b}}3–A{{music|b}}3–C4).<ref name="Patt">{{cite web |url=http://www.ralphpatt.com/Tune.html|first=Ralph|last=Patt|author-link=Ralph Patt |publisher=ralphpatt.com|work=Ralph&nbsp;Patt's jazz web page |title=The major&nbsp;3rd tuning|date=14 April 2008|access-date=10 June 2012|id=cited by {{harvtxt|Sethares|2012}} and {{harvtxt|Griewank|2010|p=1}}}}</ref> With six strings, major-thirds tuning has a smaller range than standard tuning; with seven strings, the major-thirds tuning covers the range of standard tuning on six strings.<ref name="Sethares56"/><ref name="Griewank"/> With the repetition of three open-string notes, each major-thirds tuning provides the guitarist with many options for fingering chords. Indeed, the fingering of two successive frets suffices to play pure major and minor chords, while the fingering of three successive frets suffices to play seconds, fourths, sevenths, and ninths.<ref name="Sethares56"/><ref name="Griewank2">{{harvtxt|Griewank|2010|p=2}}</ref>

For the standard Western guitar, which has six strings, major-thirds tuning has a smaller range than standard tuning; on a guitar with ''seven''&nbsp;strings, the major-thirds tuning covers the range of standard tuning on ''six''&nbsp;strings. Even greater range is possible with guitars with ''eight''&nbsp;strings.<!-- This statement is trivial. Patt is cited because he discusses 8-string guitars. --><ref name="Patt"/><ref>In the table, the last row is labeled the "7th string" so that the low C tuning can be displayed without needing another table; the term "7th string" does not appear in the sources.{{paragraph break}} Similarly, the terms "-1st string" and "0th string" do not appear in the sources, which do discuss guitars having seven-eight strings.</ref>

Major-thirds tuning was heavily used in 1964 by the American jazz-guitarist Ralph&nbsp;Patt to facilitate his style of improvisation.<ref name="Patt"/><ref name="Griewank1">{{harvtxt|Griewank|2010|p=1}}</ref>

{{clear}}

===All fourths=== right|thumb|The consecutive notes of all-fourths tuning are spaced apart by five semi-tones on the chromatic circle. thumb|right|All fourths tuning. {{main|All fourths tuning}} {{see also|Perfect fourth}}

:E2–A2–D3–G3–C4–F4 This tuning is like that of the lowest four strings in standard tuning.<ref>{{harvtxt|Sethares|2001|pp=58–59}}</ref><ref>{{Cite book |first=Bob |last=Bianco |title=Guitar in Fourths |publisher=Calliope Music |location=New York City |year=1987 |isbn=0-9605912-2-2 |oclc=16526869}}</ref> Consequently, of all the regular tunings, it is the closest approximation to standard tuning, and thus it best allows the transfer of a knowledge of chords from standard tuning to a regular tuning. Jazz&nbsp;musician Stanley&nbsp;Jordan plays guitar in all-fourths tuning; he has stated that all-fourths tuning "simplifies the fingerboard, making it logical".<ref>{{harvtxt|Ferguson|1986|p=76}}: {{cite book|chapter=Stanley Jordan|first=Jim |last=Ferguson|author-link=Jim Ferguson|pages=68–76|title=New directions in modern guitar|series=''Guitar&nbsp;Player'' basic library|editor1-first=Helen|editor1-last=Casabona |editor2-first=Adrian|editor2-last=Belew|editor2-link=Adrian Belew|publisher=Hal&nbsp;Leonard Publishing Corporation|year=1986|isbn=0881884235 |url=https://books.google.com/books?id=3idLAAAAYAAJ&q=%22Stanley+Jordan%22,+%22all+fourth%22+OR+%22perfect+fourth%22,+guitar+tuning}}</ref>

For all-fourths tuning, all twelve major&nbsp;chords (in the first or open positions) are generated by two chords, the open F&nbsp;major chord and the D&nbsp;major chord. The regularity of chord-patterns reduces the number of finger&nbsp;positions that need to be memorized.<ref name="Sethares52">{{harvtxt|Sethares|2001|p=52}}</ref>

The left-handed involute of an all-fourths tuning is an 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). Consequently, chord charts for all-fifths tunings may be used for left-handed all-fourths tuning.<ref name="Sethares53"/> {{clear}}

===Augmented fourths=== right|thumb|A line segment bisecting the chromatic circle specifies an augmented-fourths (tritone) tuning. {{Main|Augmented-fourths tuning}}

:C2–F{{music|#}}2–C3–F{{music|#}}3–C4–F{{music|#}}4 and B1–F1–B2–F3–B3–F4 etc.

Between the all-fifths and all-fourths tunings are ''augmented-fourth'' tunings, which are also called "''diminished-fifths''" or "''tritone''" tunings. It is a repetitive tuning that repeats its notes after two strings. With augmented-fourths tunings, the fretboard has greatest symmetry.<ref name="60Sethares61"/> In fact, every augmented-fourths tuning lists the notes of all the other augmented-fourths tunings on the frets of its fretboard. Professor Sethares wrote that<blockquote> "The augmented-<!-- inserted dash, here and elsewhere per WP:MOS and consistency -->fourth interval is the only interval whose inverse is the same as itself. The augmented-fourths tuning is the only tuning (other than the 'trivial' tuning <!-- notation changed from original "CCCCCC", per WP:MOS -->C–C–C–C–C–C) for which all chords-<!-- inserted dash, here and elsewhere per WP:MOS. Hyphen prevents "All chord" modifying "form", on first reading-->forms remain unchanged when the strings are reversed. Thus the augmented-fourths tuning is its own 'lefty' tuning."<ref name="Sethares60"/> </blockquote> Of all the augmented-fourths tunings, the C2–F{{music|#}}2–C3–F{{music|#}}3–C4–F{{music|#}}4 tuning is the closest approximation to the standard tuning, and its fretboard is displayed next: {| class="wikitable" |- | align="center" colspan="7" | ''Tritone'':<ref name="Sethares60">{{harvtxt|Sethares|2001|loc=[http://sethares.engr.wisc.edu/alternatetunings/regulartunings.pdf "The augmented fourths tuning", p.&nbsp;60]}}</ref> Each fret displays the open strings of <!-- exactly one -->an augmented-fourths tuning |- ! !! open<br />(0th&nbsp;fret) !! 1st fret !! 2nd fret !! 3rd fret !! 4th fret !! 5th fret |- | 1st string ! F#4 || G4 || G#4 || A4||A#4||B4 |- | 2nd string ! C4 | C#4 || D4 || D#4||E4||F4 |- | 3rd string ! F#3 || G3 || G#3 || A3||A#3||B3 |- | 4th string ! C3 | C#3 || D3 || D#3||E3||F3 |- | 5th string ! F#2 || G2 || G#2 ||A2||A#2||B2 |- | 6th string ! C2 | C#2 || D2 || D#2||E2||F2 |} An augmented-fourths tuning "makes it very&nbsp;easy for playing half-whole scales, diminished&nbsp;7 licks, and whole&nbsp;tone scales," stated guitarist Ron&nbsp;Jarzombek.<ref>{{cite web|title=Interview with Ron&nbsp;Jarzombek|first=Steve|last=Turner|author-link=Steve Turner (guitarist) |date=30 December 2005 |url=http://www.ronjarzombek.com/stevet.html |access-date=23 May 2012 |publisher=RonJarzombek.com}}.</ref> {{clear}}

===All fifths: "Mandoguitar"=== left|thumb|The consecutive open-notes of all-fifths tuning are spaced seven semi-tones apart on the chromatic circle. While the notes of the open-notes of the all-fifths and all-fourths tunings agree, their orderings are reversed. right|thumb|New standard tuning substitutes a G for the high B of all-fifths tuning {{main|All fifths}} {{See also|Quartal and quintal harmony}}

:C2–G2–D3–A3–E4–B4

All-fifths tuning is a tuning in intervals of perfect fifths like that of a mandolin, cello or violin; other names include "perfect fifths" and "fifths".<ref>{{harvtxt|Sethares|2001|loc="The mandoguitar tuning" 62–63}}</ref> Consequently, classical compositions written for violin or guitar may be adapted to all-fifths tuning more easily than to standard tuning.

When he was asked whether tuning in fifths facilitates "new intervals or harmonies that aren't readily available in standard tuning", Robert Fripp responded, "It's a more rational system, but it's also better sounding—better for chords, better for single notes." To build chords, Fripp uses "perfect intervals in fourths, fifths and octaves", so avoiding minor thirds and especially major thirds,<ref name="Mulhern" >{{harvtxt|Mulhern|1986}}: {{cite journal|first=Tom|last=Mulhern|date=January 1986|title=On the discipline of craft and art: An interview with Robert Fripp|journal=Guitar Player |url=http://www.mulhern.com/articles/Fripp.html|access-date=8 January 2013|volume=20|pages=88–103}}</ref> which are sharp in equal temperament tuning (in comparison to thirds in just intonation). It is a challenge to adapt conventional guitar-chords to new standard tuning, which is based on all-fifths tuning.<ref name="Tamm10">Musicologist Eric Tamm wrote that despite "considerable effort and search I just could not find a good set of chords whose sound I liked" for rhythm guitar. {{harv|Tamm|2003|loc=[http://www.progressiveears.com/frippbook/ch10.htm Chapter&nbsp;10: Postscript]}}</ref> Some closely voiced jazz chords become impractical in NST and all-fifths tuning.<ref name="Mandoguitar">{{harvtxt|Sethares|2001|loc="The mandoguitar tuning", pp.&nbsp;62–63}}</ref>

It has a wide range, thus its implementation can be difficult. The high ''B4'' requires a taut, thin string, and consequently is prone to breaking. This can be ameliorated by using a shorter scale length guitar, by shifting to a different key, or by shifting down a fifth. All-fifths tuning was used by the jazz-guitarist Carl Kress.

The left-handed involute of an all-fifths tuning is an all-fourths tuning. All-fifths tuning is based on the perfect fifth (seven semitones), and all-fourths tuning is based on the perfect fourth (five semitones). Consequently, chord charts for all-fifths tunings are used for left-handed all-fourths tuning.<ref name="Sethares53"/>

All-fifths tuning has been approximated with tunings in the Through The Looking Glass Guitar<ref>{{Cite web|url=https://patents.google.com/patent/JP6709929B2/ja?oq=6709929|title=日本特許第6709929号 【発明の名称】弦楽器 【特許権者】中野 圭|accessdate=2023-06-30|website=patents.google.com}}</ref> of Kei Nakano, which has been played by him since 2015. This new tuning is like a mirror to all kinds of string instruments including guitar. Also it can adapt to any other tunings of guitar. If tuned to usual conventional guitar for the right handed person, it is able to use for lefty guitar in general, and vice versa.

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====New standard tuning==== thumb|right|New standard tuning. right|thumb|alt=Audio file of New Standard Tuning's open notes.|New Standard Tuning's open strings. {{main|New standard tuning}} {{see also|Guitar Craft}}

All-fifths tuning has been approximated with tunings that avoid the high B4 or the low C2. The B4 has been replaced with a G4 in the new standard tuning (NST) of King&nbsp;Crimson's Robert&nbsp;Fripp. The original version of NST was all-fifths tuning. However, in the 1980s, Fripp never attained the all fifth's high&nbsp;B4. While he could attain&nbsp;A4, the string's life-time distribution was too short. Experimenting with a g&nbsp;string, Fripp succeeded. "Originally, seen in 5ths. all the way, the top string would not go to&nbsp;B. so, as on a tenor banjo, I adopted an&nbsp;A on the first string. These kept breaking, so&nbsp;G was adopted."<ref name="Fripp2010">{{cite web|title=Robert Fripp's diary: Friday, 5th February 2010|date=5 February 2010|first=Robert|last=Fripp|author-link=Robert Fripp|publisher=Discipline Global Mobile, DGM&nbsp;Live!|url=http://www.dgmlive.com/diaries.htm?entry=16789 |url-status=dead|archive-url=https://web.archive.org/web/20131111165420/http://www.dgmlive.com/diaries.htm?entry=16789|archive-date=11 November 2013}}</ref> In 2012, Fripp experimented with&nbsp;A String (0.007);<ref name="Fripp2012">{{cite web|title=Robert&nbsp;Fripp's diary: Sunday, 22nd&nbsp;April 2012|date=22 April 2012|first=Robert|last=Fripp|publisher=Discipline Global Mobile, DGM&nbsp;Live!|url=http://www.dgmlive.com/diaries.htm?entry=21688 |url-status=dead|archive-url=https://web.archive.org/web/20131111165336/http://www.dgmlive.com/diaries.htm?entry=21688|archive-date=11 November 2013}}</ref><ref>[http://octave4plus.com/ Octave4Plus of Gary Goodman]</ref> if successful, the experiment could lead to "the NST 1.2", CGDAE-A, according to Fripp.<ref name="Fripp2012"/> Fripp's NST has been taught in Guitar&nbsp;Craft courses.<ref>{{citation|title=Robert&nbsp;Fripp: From crimson&nbsp;king to crafty&nbsp;master|first=Eric|last=Tamm|url=http://www.progressiveears.com/frippbook/ch10.htm |year=2003|orig-year=1990|publisher=Faber and Faber (1990) |isbn=0-571-16289-4 |edition=Progressive Ears |access-date=25 March 2012|url-status=dead |archive-url=https://web.archive.org/web/20111026180438/http://www.progressiveears.com/frippbook/ch10.htm |archive-date=26 October 2011}} [http://www.erictamm.com/rf.zip Zipped Microsoft Word Document]</ref><ref name="Zwerdling">{{cite journal|first=Daniel|last=Zwerdling|author-link=Daniel Zwerdling|location=Washington DC|title=California Guitar Trio|edition=NPR Weekend|journal=All Things Considered|publisher=NPR|access-date=25 March 2012 |date=5 September 1998 |url=https://www.npr.org/templates/story/story.php?storyId=1006483}}</ref> Guitar&nbsp;Craft and its successor Guitar Circle have taught Fripp's tuning to three-thousand students.<ref name="Fripp11">{{harvtxt|Fripp|2011|p=3}}: {{cite book|last=Fripp|first=Robert|author-link=Robert Fripp|title=Seven Guitar&nbsp;Craft themes: Definitive scores for guitar ensemble|publisher=Partitas Music|year=2011 |editor-first=Horacio|editor-last=Pozzo|url=http://partitasmusic.com/ |id=ISMN&nbsp;979-0-9016791-7-7. DGM&nbsp;Sku&nbsp;partitas001|edition=First limited|others="Original transcriptions by Curt&nbsp;Golden", "Layout scores and tablatures: Ariel&nbsp;Rzezak and Theo&nbsp;Morresi"}}</ref>

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===Extreme intervals=== For regular tunings, intervals wider than a perfect fifth or narrower than a minor third have, thus far, had limited interest.

====Wide intervals==== {{anchor|Minor_sixths}}{{anchor|Minor_sixth}} Two regular-tunings based on sixths, having intervals of minor&nbsp;sixths (eight semitones) and of major&nbsp;sixths (nine semitones), have received scholarly discussion.<ref name="SetharesMajor6Minor">{{harvtxt|Sethares|2001|pp=64–67}}</ref> The chord charts for minor-sixths tuning are useful for left-handed guitarists playing in major-thirds tuning; the chord charts for major-sixths tuning, for left-handed guitarists playing in minor-thirds tuning.<ref name="Sethares53"/>

The regular tunings with minor-seventh (ten semitones) or major-seventh (eleven semitones) intervals would make conventional major/minor chord-playing very difficult, as would octave intervals.<ref name="Sethares53"/>

====Narrow intervals==== There are regular-tunings that have as their intervals either zero semi-tones (unison), one semi-tone (minor second), or two semi-tones (major second). These tunings tend to increase the difficulty in playing the major/minor system chords of conventionally tuned guitars.<ref name="Sethares53"/>

The "trivial" class of unison tunings (such as C3–C3–C3–C3–C3–C3) are each their own left-handed tuning.<ref name="Sethares53"/> Unison tunings are briefly discussed in the article on ostrich tunings. Having exactly one note, unison tunings are also ostrich tunings, which have exactly one pitch class (but may have two or more octaves, for example, E2, E3, and E4'); non-unison ostrich tunings are not regular.

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==Left-handed involution== {{See also|Interval inversion|chord inversion|involution (mathematics)}}

The class of regular tunings is preserved under the involution from right-handed to left-handed tunings, as observed by William Sethares.<ref name="Sethares53"/> The present discussion of left-handed tunings is of interest to musical theorists, mathematicians, and left-handed persons, but may be skipped by other readers.

For left-handed guitars, the ordering of the strings reverses the ordering of the strings for right-handed guitars. For example, the left-handed involute of the standard tuning E–A–D–G–B–E is the "lefty" tuning E–B–G–D–A–E. Similarly, the "left-handed" involute of the "lefty" tuning is the standard ("righty") tuning.<ref name="Sethares53"/>

The reordering of open-strings in left-handed tunings has an important consequence. The chord fingerings for the right-handed tunings must be changed for left-handed tunings. However, the left-handed involute of a regular tuning is easily recognized: it is another regular tuning. Thus the chords for the involuted regular-tuning may be used for the left-handed involute of a regular tuning.

For example, the right-handed version of all-fourths tuning is all-fifths tuning, and the left-handed version of all-fifths tuning is all-fourths tuning. In general, the left-handed involute of the regular tuning based on the interval with&nbsp;<math>n</math>&nbsp;semitones is the regular tuning based on its involuted interval with&nbsp;<math>12-n</math>&nbsp;semitones: All-fourths tuning is based on the perfect fourth (five semitones), and all-fifths tuning is based on the perfect fifth (seven semitones), as mentioned previously.<ref name="Sethares53">{{harvtxt|Sethares|2001|p=53}}</ref> The following table summarizes the lefty-righty pairings discussed by Sethares.<ref name="Sethares53"/>

{| class="wikitable" |+ Left-handed tunings<ref name="Sethares53"/> |- ! Right-handed !! Left-handed |- | Minor thirds|| Major sixths |- | Major thirds|| Minor sixths |- | All fourths|| All fifths |- | Augmented fourths || Diminished fifths |- | All fifths || All fourths |- | Minor sixths|| Major thirds |- | Major sixths|| Minor thirds |} The left-handed involute of a left-handed involute is the original right-handed tuning. The left-handed version of the trivial tuning C–C–C–C–C–C is also C–C–C–C–C–C. Among non-trivial tunings, only the class of augmented-fourths tunings is fixed under the lefty involution.<ref name="Sethares53"/><ref name="60Sethares61">{{harvtxt|Sethares|2001|loc="The augmented&nbsp;fourths tuning" 60–61}}</ref>

==Summary== The principal regular-tunings have their properties summarized in the following table: {| class="wikitable" |- ! Regular tuning !! Interval<br />(Number of semitones) !! Repetition !! Advantages:<br />Each facilitates learning and improvisation. !! Disadvantages:<br />None use standard-tuning's open chords.!! Left-handed<br />involution<ref name="Sethares53"/> !!Guitarist(s) <!-- |- | Minor thirds|| Minor third (3) || After 4 strings || ''not discussed'' (''nd'') || ''nd'' || ''nd'' --> |- | Major thirds|| Major third (4) || After 3 strings || * Chromatic scale on four successive frets. * Hence, reduced hand-stretching: **Major and minor chords are played on 2 successive frets; **others (seconds, fourths, sevenths, and ninths) on 3.<ref name="Griewank2"/> || * Smaller range (without 7 strings) * Only three open-notes. || Minor-sixth tuning || Ralph Patt |- | All fourths || Perfect fourth (5) || Non-repetitive<ref name="RepetitiveFootnote" >No repetition occurs in six strings; repetition occurs after 12 strings.</ref> || * Uses chords from lowest 4 strings of standard tuning. * Same tuning as bass guitar || Difficult to play folk chords || All-fifths tuning ||Stanley Jordan |- | Augmented fourths|| Tritone (6) || After 2 strings|| symmetry ("left-handed")|| Only 2 open&nbsp;notes || Augmented-fourths tuning ||Shawn Lane |- | All fifths || Perfect fifth (7) || Non-repetitive<ref name="RepetitiveFootnote"/> || * Wide scope facilitates ensemble playing and single-note picking (rather than conventional chords) * Natural for all-fifths music (violin, cello, mandolin) || * Very difficult to play conventional chord-voicings. * Requires extreme (light and heavy) strings. || All-fourths tuning || * Carl Kress * Kei Nakano |}

==Notes== {{Reflist}}

==References== * {{Cite book | title = The guitar handbook | first = Ralph | last = Denyer | others = Special contributors Isaac&nbsp;Guillory and <!-- NOT Alastair Crawford -->Alastair&nbsp;M.&nbsp;Crawford | pages =65–160 | chapter=Playing the guitar ('How the guitar is tuned', pp.&nbsp;68–69, and 'Alternative tunings', pp.&nbsp;158–159) | isbn = 0-330-32750-X | location = London and Sydney | publisher = Pan Books | edition= Fully revised and updated | year = 1992 }} * {{citation |last=Griewank |first=Andreas |title=Tuning guitars and reading music in major thirds |date=1 January 2010 |archive-url=https://web.archive.org/web/20220807005527/https://opus4.kobv.de/opus4-matheon/frontdoor/deliver/index/docId/675/file/7046_mathtune.pdf|archive-date=2022-08-07|url=https://opus4.kobv.de/opus4-matheon/frontdoor/deliver/index/docId/675/file/7046_mathtune.pdf|url-status=dead |series=Matheon preprints |volume=695 |publisher=DFG research center "MATHEON, Mathematics for key technologies" |location=Berlin, Germany |id=MSC-Classification 97M80 Arts. Music. Language. Architecture. }} * {{cite book|year=2001|chapter=Regular tunings|title=Alternate tuning guide|first=Bill|last=Sethares|author-link=William Sethares|pages=52–67 |url=http://sethares.engr.wisc.edu/alternatetunings/regulartunings.pdf |publisher=University of Wisconsin; Department of Electrical Engineering|location=Madison, Wisconsin|access-date=19 May 2012}} * {{cite book|date=10 January 2009|title=Alternate tuning guide|first=Bill|last=Sethares|author-link=William Sethares|url=http://sethares.engr.wisc.edu/alternatetunings/alltunings.pdf|orig-year=2001|publisher=University of Wisconsin; Department of Electrical Engineering|location=Madison, Wisconsin|access-date=19 May 2012}} * {{cite web|title=Alternate tuning guide|first=William A.|last=Sethares|author-link=William Sethares|date=18 May 2012|url=http://sethares.engr.wisc.edu/alternatetunings/alternatetunings.html|publisher=University of Wisconsin; Department of Electrical Engineering|location=Madison, Wisconsin|access-date=8 December 2012}}

==Further reading== * {{cite web|url=http://sethares.engr.wisc.edu/alternatetunings/alternatetuningsInteractive.html |title=Alternate&nbsp;tuning guide: Interactive|first=William A.|last=Sethares|author-link=William Sethares |access-date=27 June 2012 |date=12 May 2012|ref=none}} Uses Wolfram Cdf player. * {{cite book|title=Guitar Tunings: A Comprehensive Guide|first=Dick|last=Weissman|author-link=Dick Weissman |url=https://books.google.com/books?id=-rRf8x53_1gC&q=Dick+Weissman,+Guitar+tuning |publisher=Routledge|year=2006|lccn=0415974410|isbn=9780415974417|ref=none}}

==External links== {{wikibooks|Guitar|Alternate Tunings|Alternative tunings}}

===Major thirds=== * Professors Andreas Griewank and William Sethares each recommend discussions of major-thirds tuning by two jazz-guitarists, {{harv|Sethares|2012|loc="[http://sethares.engr.wisc.edu/alternatetunings/alternatetunings.html Regular tunings]"}} and {{harv|Griewank|2010|p=1}}: ** [https://web.archive.org/web/20150411064851/http://v3p0.m3guitar.com/ Ole&nbsp;Kirkeby for 6- and 7-string guitars]: Charts of [https://web.archive.org/web/20120726002836/http://v3p0.m3guitar.com/html/fretmaps_intervals.html intervals] [https://web.archive.org/web/20120725085754/http://v3p0.m3guitar.com/html/fretmaps_chords_major.html major chords], and [https://web.archive.org/web/20120725085759/http://v3p0.m3guitar.com/html/fretmaps_chords_minor.html minor chords], and [https://web.archive.org/web/20120725090129/http://v3p0.m3guitar.com/html/strings.html recommended gauges for strings]. ** [http://www.ralphpatt.com/Tune.html Ralph&nbsp;Patt for 6-, 7-, and 8-string guitars]: Charts of [http://www.ralphpatt.com/Tune/Scales.html scales], [http://www.ralphpatt.com/Tune/Chords.html chords], and [http://www.ralphpatt.com/Tune/Prog.html chord-progressions].

===New standard tuning=== * Courses in New Standard Tuning are offered by Guitar Circle, the successor of [http://www.guitarcraft.com/ Guitar Craft]: ** [http://www.guitarcircleofeurope.com/ Guitar Circle of Europe] ** [http://www.guitarcircleoflatinamerica.com/ Guitar Circle of Latin America] ** [http://www.guitarcircleofnorthamerica.com/ Guitar Circle of North America]

{{Guitar tunings|Regular}}

{{DEFAULTSORT:Regular tunings}} Category:Regular guitar-tunings Category:Combinatorial design Category:Intervals (music)

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