DADGBE Online Guitar Tuner - Drop D Guitar Tuning

Online Guitar Tuner comments on DADGBE Guitar Tuner - Dropped D Guitar Tuning:

This tuning allows playing of power chords (5th chords) by holding the lowest three strings with only one finger, and therefor is mostly used in metal music. Not only it's easier to play metal riffs, but it also gives a low edge and darker sound to a guitar playing because the lowest tone on a guitar is two semitones lower than in standard guitar tuning.