Doom metal is an extreme form of heavy metal music that typically uses very slow tempos, low-tuned guitars and a much 'thicker' or 'heavier' sound than other metal genres. Both the music and the lyrics intend to evoke a sense of despair, dread, and impending doom. The genre is strongly influenced by the early work of Black Sabbath, who formed a prototype for doom metal with songs such as "Black Sabbath" and "Into the Void". During the first half of the 1980s, a number of bands from England (Pagan Altar, Witchfinder General) and the United States (Pentagram, Saint Vitus, Trouble) defined doom metal as a distinct genre.