Extreme metal acts set themselves apart from traditional heavy metal acts, such as Iron Maiden, Judas Priest and Motörhead, by incorporating more abrasive musical characteristics such as higher tempos, increased aggression and a harsher extremity. In the majority of the world, extreme metal does not receive much radio-play or achieve high chart positions.
Extreme metal's sonic excess is characterized by high levels of distortion (also in the vocals – grunting or screaming), less focus on guitar solos and melody, emphasis on technical control, and fast tempos (at times, more than 200 beats per minute). Its thematic transgression can be found in more overt and/or serious references to Satanism and the darker aspects of human existence that are considered out of bounds or distasteful, such as death, suicide and war." "Visual transgression [can include] ... medieval weaponry [and] bloody/horrific artwork."
According to ethnographer Keith Kahn-Harris, the defining characteristics of extreme metal can all be regarded as clearly transgressive: the "extreme" traits noted above are all intended to violate or transgress given cultural, artistic, social or aesthetic boundaries. Kahn-Harris states that extreme metal can be "close to being ... formless noise", at least to the uninitiated listener.:33 He states that with extreme metal lyrics, they often "offer no possibility of hope or redemption" and lyrics often reference apocalyptic themes. Extreme metal lyrics often describe Christianity as weak or submissive,:40 and many songs express misanthropic views such as "kill every thing".:40 A small number of extreme metal bands and song lyrics make reference to far-right politics; for example, the Swedish black metal band Marduk has commonly referenced the Nazi Panzer tanks, which can be seen in works such as Panzer Division Marduk (1999).:41