Going one step beyond other metal genres, death metal is a type of music known for extremely rough and/or incomprehensible vocals, and particularly macabre subject matter. Often, if lyrics are not available in printed form, they cannot be understood. This style of music is known for very abrupt tempo and count changes, and extremely fast drumwork. Almost all bands using this style use double bass drums.
A subset of death metal is 'symphonic' or 'melodic' death metal, where much more attention is paid to melody and harmony, often using synthesizers or other non-standard instruments.