A Drop-D tuning involves simply dropping the E string (6th string) to a D. This tuning is commonly used in Heavy Metal Music, but also in Flamenco Zambra.
Heavy metal beginners like this tuning as it allows them to do “power chords” with just one finger. See some of the video demos below to see some simple techniques.
Ten riffs using a Drop D tuning:
Drop D Tuning Lesson: