In guitar playing, a common meaning for open tuning is one where the strings are tuned so that a chord is achieved without fretting, or pressing any of the strings; using such a tuning other chords may be played by simply barreing a fret, or through the use of a slide. The ultimate true meaning of open tuning is anything that a guitar can be tuned in (including standard tuning). Open Tuning = whatever the guitar is tuned to, open.
Open tunings are common in blues music and some rock and folk music.
In Hawai`ian Music, for Slack-key guitar, an example would be the taro patch, or open 'G' tuning, with strings low-high; D-G-D-G-B-D.
Notable players who make extensive or exclusive use of open tunings include Richard Thompson, Martin Carthy, Blind Blake, Jimmy Page, Keith Richards, Leo Kottke, Richie Havens, Joni Mitchell, Jonatha Brooke, Michael Hedges, and Ted Hawkins.
Tunings can be named anything a player would like them to be called. There are many 'Open C' tunings. A player could call them by colors or moods. The whole purpose of open tunings is to free the player from compulsive naming & Western approaches to playing instruments that can be tuned to an array of possibilities. A standard acoustic guitar can reach nearly 150,000 different tunings. There is still an infinite amount of uncharted territory in the world of open tunings. This territory can provide every player on earth their own chord vocabulary.
Major open tunings (giving a major chord with the open strings) include:
- Open A: low-high; E-A-C#-E-A-E
- Alternatively: low-high; E-A-C#-E-A-C#
- Slide Open A: low-high; E-A-E-A-C#-E
- Open C: low-high; C-G-C-G-C-E
- Open D: low-high; D-A-D-F#-A-D
- Alternatively: low-high; D-A-D'-A'-D-D
- Open E: low-high; E-B-E-G#-B-E (use light gauge strings because two strings must be raised)
- Open F: low-high; F-A-C-F-C-F (rare)
- Open G: low-high; D-G-D-G-B-D
- dobro or Russian Open G: low-high; G-B-D-G-B-D (occasionally adopted for ordinary guitar, but requires lighter fifth and sixth strings)
The above open tunings all give a major chord with open strings. Since it is highly likely guitarists will need to play minor chords as well, open tunings must be adapted to allow this by lowering the pitch of one of the strings forming the open chord by half a step. To avoid the relatively cumbersone designation "open D minor", "open C minor", such tunings are sometimes called "crossnote tunings". The term also expresses the fact that, by fretting the lowered string at the first fret, it is possible to produce a major chord very easily.
Crossnote tunings include:
- Crossnote A: low-high; E-A-E-A-C-E
- Alternative: E-A-C-E-A-E (rare)
- Crossnote C: low-high; C-G-C-G-C-Eb
- Open D: low-high; D-A-D-F-A-D
- Crossnote E: low-high; E-B-E-G-B-E
- Crossnote F: low-high; F-Ab-C-F-C-F (extremely rare)
- Alternative: low-high; F-C-F-Ab-C-F (used by Albert Collins; requires extremely light gauges
- Crossnote G: low-high; D-G-D-G-Bb-D
Sometimes a guitarist will want a tuning that will permit very easy chords but not be defintively minor or major. In this case, modal tunings can be used. They can be especially effective with droning open strings, and give "suspended" second or fourth chords:
Modal tunings include:
- Csus2: low-high; C-G-C-G-C-D
- Csus4: low-high; C-G-C-G-C-F
- Dsus2: low-high; D-A-D-E-A-D
- Dsus4: low-high; D-A-D-G-A-D (very popular in Celtic music)
- Esus2: low-high; E-A-E-F#-B-E
- Esus4: low-high; E-A-E-A-B-E
- Gsus2: low-high; D-G-D-G-A-D
- Gsus4: low-high; D-G-D-G-C-D
Extended Chord Tunings
These tunings allow a guitarist to play an open seventh, ninth, eleventh or thirteenth chord. One or more of the strings is retuned to the appropriate note of the required scale. Such tunings may be either minor or major.
- Open Dmaj7: low-high; D-A-D-F#-A-C#
- Open Dmin7: low-high; D-A-D-F-A-C
- Open G6: low-high; D-G-D-G-B-E
- Dobro open G6: low-high; G-B-D-G-B-E (two lowest strings tuned up and require lighter gauges)
- Open G7: low-high; D-G-D-G-B-F or F-G-D-G-B-D
- Modal G7: low-high; F-G-D-G-C-D
- Open G6min7: low-high; F-G-D-G-B-E
- Open Cmin7: low-high; C-G-C-G-Bb-Eb
- Open C7: low-high; C-G-C-G-B-E
These open tunings offer much room for experiment, but can only be used in a few keys. (Courtsy of Wikipedia)
Any guitar tuning other than the Standard (EADGBE) Tuning is referred to as an Alternate Tuning. It is a good idea to invest in an electronic tuner before you start to explore Alternate Tunings. Below is a quick listing of common alternate tunings with links to tuning instructions as available.