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. Open tunings are common in blues and folk music, and they are used in the playing of slide and bottleneck guitars.
Dobros use a full six-string tuning with a bottom G: G-B-D-G-B-D, low to high. The two lowest strings are, accordingly, tuned three semitones higher for the lowest string (from E up to G) and two semitones higher for the second-lowest string (from A up to B), relative to standard tuning.
The 5-String Banjo's standard tuning is also an Open G: g-D-G-B-D, where the lower case "g" denotes the highest-pitched string, physically located next to (above) the lowest-pitched string, the first upper case "D".
Overtones of the fundamental note G
Joni Mitchell used the open-G overtones-tuning G-G-D-G-B-D for "Electricity", "For the Roses", and "Hunter (The Good Samaritan)".
Zebra's Randy Jackson played "Who's Behind The Door?" using the same open-G overtones-tuning.
The Rolling Stones's Keith Richards plays a five-string 1953 Telecaster in open-G tuning.
Bellow (1970, p. 164): Bellow, Alexander (1970). The illustrated history of the guitar. Colombo Publications.
Timofeyev (1999): Timofeyev, Oleg V. (1999). The golden age of the Russian guitar: Repertoire, performance practice, and social function of the Russian seven-string guitar music, 1800-1850. Duke University, Department of Music. pp. 1–584. University Microfilms (UMI), Ann Arbor, Michigan, number 9928880.
Ophee, Matanya (ed.). 19th Century etudes for the Russian 7-string guitar in G Op. The Russian Collection 9. Editions Orphee. PR.494028230.
Ophee, Matanya (ed.). Selected Concert Works for the Russian 7-String Guitar in G open tuning. The Russian Collection. 10 ("X"). Editions Orphee. PR.494028240.
Sharken, Lisa (15 May 2001). "Mick Ralphs: The rock 'N' roll fantasy continues". Vintage Guitar. Retrieved 21 February 2013.
"List of all Guitar and Piano Transcriptions". GGDGBD. JoniMitchell.com. Retrieved February 22, 2013.
Ellis, Andy (2005). "How to play like ... Keith Richards". Guitar Player. (subscription required). Retrieved 24 March 2013.
Denyer, Ralph (1992). "Playing the guitar ('How the guitar is tuned', pp. 68–69, and 'Alternative tunings', pp. 158–159)". The guitar handbook. Special contributors Isaac Guillory and Alastair M. Crawford (Fully revised and updated ed.). London and Sydney: Pan Books. pp. 65–160. ISBN 0-330-32750-X.
Sethares, William A. (2011). "Alternate tuning guide". Madison, Wisconsin: University of Wisconsin; Department of Electrical Engineering. 2010 PDF version by Bill Sethares. Retrieved 19 May 2012.
Weissman, Dick (2006). Guitar tunings: A comprehensive guide. Routledge. ISBN 9780415974417. LCCN 0415974410.