In the sixteenth century, the notes of A–D–G–B–E were adopted as a tuning for guitar-like instruments, and the low E was added later to make E–A–D–G–B–E as the standard guitar tuning. In open tuning the strings are tuned to sound a chord when not fretted, and is most often major. Open tunings commonly used with slide guitar include open D or Vestapol tuning: D–A–D–F–A–D; and open G or Spanish tuning: D–G–D–G–B–D. Open E and open A, formed by raising each of those tunings a whole tone, are also common. Other tunings are also used, in particular the drop D tuning (low E string tuned down to D) is used by many slide players. This tuning allows for power chords, which contain root, fifth and eighth (octave) notes in the bass strings and conventional tuning for the rest of the strings. Robert Johnson, whose playing has been cited by Eric Clapton, Keith Richards, Jimi Hendrix, and Johnny Winter as being a powerful influence on them, used tunings of standard, open G, open D, and drop D.
In the sixteenth century the notes of A–D–G–B–E were adopted as a tuning for guitar-like instruments and the low E was added later to make E–A–D–G–B–E as the standard guitar tuning In open tuning the strings are tuned to sound a chord when not fretted and is most often major Open tunings commonly used with slide guitar include open D or Vestapol tuning D–A–D–F–A–D; and open G or Spanish tuning D–G–D–G–B–D Open E and open A formed by raising each of those tunings a whole tone are also common Other tunings are also used in particular the drop D tuning (low E string tuned down to D) is used by many slide players This tuning allows for power chords which contain root fifth and eighth (octave) notes in the bass strings and conventional tuning for the rest of the strings Robert Johnson whose playing has been cited by Eric Clapton Keith Richards Jimi Hendrix and Johnny Winter as being a powerful influence on them used tunings of standard open G open D and drop D