dropD
Drop D is an alternate guitar tuning in which the low E string is tuned down a whole step from E2 to D2, while the remaining strings stay in standard tuning (E A D G B E). This lowers the overall pitch and gives the instrument a heavier, deeper low end without changing most of the familiar chord shapes.
The tuning is particularly popular for riff-based styles because it enables easy power chords and droning patterns
Drop D is part of a broader family of drop tunings in which the lowest string is