Guitar lessons - Tuning

Tuning

Notationally, the guitar is considered a transposing instrument. Its pitch sounds one octave lower than it is notated on a score.

Standard

In standard tuning, the C-major chord has three shapes because of the irregular major-third between the G- and B-strings.

A variety of tunings may be used. The most common tuning, known as "Standard Tuning", has the strings tuned from a low E, to a high E, traversing a two octave range?EADGBE. When all strings are played open the resulting chord is an Em7/add11.

The pitches are as follows:

String	Scientific pitch	Helmholtz pitch	Interval from middle C	Frequency (Hz)
1st	E4	e'	major third above	329.63
2nd	B3	b	minor second below	246.94
3rd	G3	g	perfect fourth below	196.00
4th	D3	d	minor seventh below	146.83
5th	A2	A	minor tenth below	110.00
6th	E2	E	minor thirteenth below	82.41

The table below shows a pitch's name found over the six strings of a guitar in standard tuning, from the nut (zero), to the twelfth fret.

0	1	2	3	4	5	6	7	8	9	10	11	12
E	F	F?	G	A?	A	B?	B	C	C?	D	E?	E
B	C	C?	D	E?	E	F	F?	G	A?	A	B?	B
G	A?	A	B?	B	C	C?	D	E?	E	F	F?	G
D	E?	E	F	F?	G	A?	A	B?	B	C	C?	D
A	B?	B	C	C?	D	E?	E	F	F?	G	A?	A
E	F	F?	G	A?	A	B?	B	C	C?	D	E?	E

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.

For four strings, the 5th fret on one string is the same open-note as the next string; for example, a 5th-fret note on the sixth string is the same note as the open fifth string. However, between the second and third strings, an irregularity occurs: The 4th-fret note on the third string is equivalent to the open second string.

Alternative

Chords can be shifted diagonally in major-thirds tuning and other regular tunings. In standard tuning, chords change their shape because of the irregular major-third G-B.

Standard tuning has evolved to provide a good compromise between simple fingering for many chords and the ability to play common scales with reasonable left-hand movement. There are also a variety of commonly used alternative tunings, for example, the classes of open, regular, and dropped tunings.

Ry Cooder plays slide-guitar with open tunings.

Open tuning refers to a guitar tuned so that strumming the open strings produces a chord, typically a major chord. The base chord consists of at least 3 notes and may include all the strings or a subset. The tuning is named for the open chord, Open D, open G, and open A are popular tunings. All similar chords in the chromatic scale can then be played by barring a single fret. Open tunings are common in blues and folk music, and they are used in the playing of slide and bottleneck guitars. Many musicians use open tunings when playing slide guitar.

For the standard tuning, there is exactly one interval of a major third between the second and third strings, and all the other intervals are fourths. 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.

In contrast, regular tunings have equal intervals between the strings, and so they have symmetrical scales all along the fretboard. This makes it simpler to translate chords. For the regular tunings, chords may be moved diagonally around the fretboard. The diagonal movement of chords is especially simple for the regular tunings that are repetitive, in which case chords can be moved vertically: Chords can be moved three strings up (or down) in major-thirds tuning 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.

On the other hand, some chords are 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, in which the large spacings require hand stretching. Some chords, which 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.

• In major-thirds tuning, the interval between open strings is always a major third. Consequently, four frets suffice to play the chromatic scale. Chord inversion is especially simple in major-thirds tuning. Chords are inverted simply by raising one or two notes by three strings. The raised notes are played with the same finger as the original notes. In contrast, in standard tuning, the shape of inversions depends on the involvement of the irregular major-third.
• All-fourths tuning replaces the major third between the third and second strings with a fourth, extending the conventional tuning of a bass guitar. With all-fourths tuning, playing the triads is more difficult, but improvisation is simplified, because chord-patterns remain constant when moved around the fretboard. Jazz guitarist Stanley Jordan uses the all-fourths tuning EADGCF. Invariant chord-shapes are an advantage of other regular tunings, such as major-thirds and all-fifths tunings.
• Extending the tunings of violins and cellos, all-fifths tuning offers an expanded range CGDAEB, which however has been impossible to implement on a conventional guitar. All-fifths tuning is used for the lowest five strings of the new standard tuning of Robert Fripp and his former students in Guitar Craft courses; new standard tuning has a high G on its last string CGDAE-G.

Another class of alternative tunings are called drop tunings, because the tuning drops down the lowest string. Dropping down the lowest string a whole tone results in the "drop-D" (or "dropped D") tuning. Its open-string notes DADGBE (from low to high) allow for dominant basses in the keys of D and D minor. It simplifies the playing of simple fifths (powerchords). Many contemporary rock bands re-tune all strings by several semi-tones, making, for example, Drop-C or Drop-B tunings.

Scordatura

Many scordatura have been used on the guitar. A common form of scordatura involves tuning the 3rd string to F? to mimic the standard tuning of the lute, especially when playing renaissance repertoire originally written for that instrument.