Theory overview
The notes in this tuning
form the 3 notes of the G major triad (the basic G major chord). These 3
notes are (D, G, B). When you play the strings open you will get a G major chord.
Just like with all open
tunings, it is very good for instrumental acoustic pieces, it's very popular
among slide guitarists as well. You can play any chord you wish, simply by
holding down all the strings at a single fret.
This form of guitar
tuning is used by bands such as The Rolling Stones, and Led Zeppelin.