Among alternative tunings for the guitar, an open G tuning is an open tuning that features the G-major chord; its open notes are selected from the notes of a G-major chord, such as the G-major triad (G,B,D). For example, a popular open-G tuning is
An open-G tuning allows a G-major chord to be strummed on all six strings with neither fretting of the left hand nor a capo. Like other open tunings, it allows the eleven major chords besides G major each to be strummed by barring at most one finger on exactly one fret.[1]