Alternative metal
Nu metal bands including Deftones and Slipknot went one step further and decided to tune "drop" tuning even lower. By lowering the 6th string one whole step in lowered tunings they created a heavier and grittier sound. Lower tunings such as Drop D, used prior by groups such as Nirvana and Alice In Chains, Drop C, Drop B, Drop B, and Drop A were utilized. These tunings are very popular among Alternative metal, metalcore and deathcore acts like Trivium, Emmure, Breaking Benjamin, August Burns Red, and Suicide Silence, where fast chord changes are an essential part of the sound. Progressive metal acts such as Pain of Salvation, Opeth, Fates Warning and Dream Theater use these tunings in some of their E-tuned songs.