In recent years, the guitar has become an almost universal instrument, used in most styles of music. Following the natural inclination of folk musicians to use whatever instruments are readily available, the guitar has become an important part of many world music traditions.
While the guitar's normal tuning of EADGBE makes it quite easy to play the simple major and minor chords of pop and rock music, and the densely clustered chords found in jazz, it's not particularly well-suited to many styles of world music.
Most traditional music is modal in nature, rather than major or minor, and the harmonies that go well with modal tunes are drones (long continuous bass notes) and more widely spaced chords — often using only the root and fifth without the third of the chord, thereby creating an ambiguity between major and minor.
Many guitarists in traditional music use other tunings to make it easier to play these chords.
DADGAD tuning was developed by English folk guitarist Davey Graham in the early 1960s and quickly adopted by many traditional players for accompanying tunes. It has become the dominant tuning amongst Irish traditional players such as Kate Burke from Trouble in the Kitchen, and Donogh Hennessy from Lúnasa. It has also spread beyond traditional music circles to become common among rock musicians who are influenced by traditional music, like Neil Young and Jimmy Page from Led Zeppelin.
Many other guitarists have devised their own similar open tunings, for example Martin Carthy often uses CGCDGA.
Open tunings are generally only useful for a handful of keys, so most traditional guitarists use a capo to play in different keys. Many of the chord shapes involve combining notes played high up the fret board with open drone strings. Barre chords are not common.
It's possible to play a melody on the guitar but this is best done solo, as guitar melodies tend to be drowned out in a session environment by louder instruments such as fiddle and flute.
Guitar players featured in The Pure Drop:
