If you have any experience with these open tunings, you know that you have the basic chords on open strings and simpel barre.
The harmonic structure of the Open-G tuning is like this: You have the root on 5th and 3rd string, the fifth on 6th, 4th and 1st string, and the third on 2nd string. In a chord, the root gives identity, the fifth gives stability and the third gives character. It is important to note that the Open-G tuning has only one third. If you loose this third by fretting the third string without playing a third at any of the other strings, the chord will loose it's character as a major chord.
The first group of chords are the basic chords on open strings and barré chords.
| Open stings and barré chords |
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| G (A) |
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C (D) |
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D (E) |
The next set is a group of variations of the G-major chord, played on the top three strings, with the bottom three strings open. As we are fretting the third string, we will no longer have the third on this string. To keep the character of a major chord, you have to play the third on one of the other strings (or 3rd string, 12th fret, as in the last example).
| Variations of the G-major chord |
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| 5-1-5-3-5-1 |
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5-1-5-5-1-3 |
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5-1-5-1-3-3 |
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5-1-5-1-3-5 |
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| 5-1-1-3-5-5 |
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5-1-3-7-1-5 |
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5-1-5-1-3-5 |
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You can also leave the 2nd string open, and then you do not have to worry about the third. You can actually leave any string open, but then we will play melody over an open chord, more than various chord shapes. They are all, but one, based on the 6 three string major chord shapes. They are movable positions. If the chord you are playing contains either a G or D, you can include one or more open strings.
| Three string major chord shapes |
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| X-X-X-1-3-5 (root) |
X-X-X-3-5-1 (1. inv) |
X-X-X-5-1-3 (2. inv) |
X-X-1-3-5-X (root) |
X-X-3-5-1-X (1. inv) |
X-X-5-1-3-X (2. inv) |
The next primary chord is C.(or D if you are in open E).
| C (D) chord |
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C7 (D7) |
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| X-5-3-5-1-3 |
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X-5-1-3-5-1 |
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X-5-3-7-1-3 |
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X-5-1-3-5-7 |
The third primary chord is D or D7 (or E and E7 if you are in open A).
| D (E) chord |
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D7 (E7) |
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| 1-5-1-5-1-3 |
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1-5-3-3-1-1 |
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1-5-3-5-7-1 |
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1-5-1-5-7-3 |
