Dropped D

Drop D tuning, also known as DADGBE (from lowest to highest string), is an alternative, or scordatura, form of guitar tuning — specifically, a dropped tuning — in which the lowest (sixth) string is tuned down ("dropped") from the usual E of standard tuning (EADGBE, from lowest to highest string) by one whole step / a tone (2 frets) to D. Drop D tuning, as well as other lowered altered tunings, are often used with the electric guitar in heavy metal music. It is also used in blues, country, folk (often with acoustic guitar), and classical guitar.

In drop D the three open bass strings form a D5 power chord. Other fifth chords are made when barred with the index finger of the fretting hand shifted up the fretboard. Drop D tuning is frequently used in heavy metal and its various subgenres, as guitarists in these styles often need fast transitions between power chords. Drop D is also used in metal because it adds two lower semitones to the bass range of the rhythm guitar, which adds two more low-range power chords (Eb and D) and enables a "heavier", deeper sound. The tuning has also been used in many other styles of music, including blues, country, folk, and classical. Due to its similarity to standard tuning, drop D is recognised as a useful introduction to alternative tunings, leading logically to an exploration of DADGAD, open D and drop D drop G (in which both the 5th and 6th strings are dropped a tone) tunings.

The tuning allows for chords with a root or bass note of D to be played with a D an octave lower than with standard tuning. It also allows the playing of open D chords that include the fifth and sixth strings, letting the full sonority of the guitar be heard. This can be especially useful for songs in the keys of D major or minor and is particularly effective on acoustic guitar. Drop D also allows fingerpickers to play chord shapes higher up the neck while maintaining an alternating bass. The bottom three strings, if left open, will vibrate sympathetically and, using chord shapes limited to the top three strings, a drone effect can easily be achieved.

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