The term refers to the the phenomenon of one's face muscles inexplicably contorting upon hearing an extremely metal riff. It is uncontrolable, many have researched it but it remains a mystery. Why do heavy ass riffs make us do this? we'll never know. Also, those who make and/or play the riffs cannot help it either, and are forced to do the metal face as well.
Put on your best metal face for the picture.
by Mory October 10, 2007