An alternate tuning is one where the strings are tuned differently from “standard” tuning (EADGBE). An alternate tuning differs from an open tuning in that the latter results in a major or minor chord, where an alternate tuning does not. Joni Mitchell is well known for her use of alternate tunings. Fingerstyle acoustic guitarists, such as Leo Kottke, Michael Hedges, Don Ross, Preston Reed, Alex de Grassi, Will Ackerman, and others make extensive use of alternate tunings, as do a number of experimental electric guitarists. DADGAD is perhaps the best-known alternate acoustic guitar tuning, and is used frequently for Celtic music. A common class of alternate tunings are the dropped tunings, such as Dropped D, where the low E string is tuned down to D.
In classical music, non-standard tuning techniques are referred to as “scordatura,” (“mistuning” in Italian) and are used on violins and other instruments. Among folk and country fiddlers, this is sometimes referred to as “cross-tuning”.
Among the advantages to using alternate tunings:
- Contrapuntal playing can be made easier.
- Impossible and difficult fingerings and intervals can made playable.
- Open strings can be utilized for drone effects, and to facilitate chordal and harmonic effects.
- The range of the instrument can be extended.