Alternative tunings
The method we now use to tune the guitar-E,A,D,G,B,E, from 6th string to 1st- is a convention that has developed over the centuries. Custom and practice have shown that it provides an acceptable range, a convenient placing of the intervals, and a manageable choice of basic chord fingerings. Of course, it is not the only system. There are countless other ways in which the strings can be tuned.
Alternative tunings generally fall into one of two categories. They are either "open" tunings, which means that the strings are tuned to sound a chord when they are all played open or unfretted, or they are adaptations of the standard tuning and are designed to feature one or more open strings as part of the piece for which they are used. Alternative tunings occur widely in folk, blues and ragtime styles, and, particularly, in bottle neck or slide playing.
Open G tuning ("slack key")
| 6th | 5th | 4th | 3rd | 2nd | 1st |
| D | G | D | G | B | D |
How to tune
6th string down to D.
5th string down to G.
4th string as normal.
3rd string as normal.
2nd string as normal.
1st string down to D.
| 6th | 5th | 4th | 3rd | 2nd | 1st |
| D | A | D | F# | A | D |
How to tune
6th string down to D.
5th string as normal.
4th string as normal.
3rd string down to F#.
2nd string down to A.
1st string down to D.
| 6th | 5th | 4th | 3rd | 2nd | 1st |
| E | B | E | G# | B | E |
How to tune
6th string as normal.
5th string up to B.
4th string up to E.
3rd string up to G#.
2nd string as normal.
1st string as normal.
Open C tuning
| 6th | 5th | 4th | 3rd | 2nd | 1st |
| C | G | C | G | C | E |
How to tune
6th string down to C.
5th string down to G.
4th string down to C.
3rd string as normal.
2nd string up to C.
1st string as normal.
D modal tuning
So-called modal tunings are, in a sense, "open" tunings. When all six strings are played open the sound is of a suspended fourth chord. This gives a very distinctive feel and is ideal for fingerstyles. The example below shows a D modal tuning. It differs from open D in that the 3rd string remains on G instead of being tuned down to F# this means that the strings give the notes D (the 4th note) and A (the 5th note). Together, the 1st, 4th and 5th produce a suspended fourth chord.
| 6th | 5th | 4th | 3rd | 2nd | 1st |
| D | A | D | G | A | D |
How to tune
6th string down to D.
5th string as normal.
4th string as normal.
3rd string as normal.
2nd string down to A.
1st string down to D.
All modal tunings contain the 1st, 4th and 5th notes of the major scale in the key that give them their name. In D modal, these notes are D (1 st), G (4th) and A (5th).