This article explores reasons for the proliferation of dissonance in metal music. It asks why metal musicians compose dissonant songs and what sociocultural functions dissonance may have for metal as a community. The findings suggest that exploring ways to further utilize dissonance is crucial to the genre’s development and continued transgression, especially in progressive and extreme subgenres, and that fans derive pleasure and meaning from dissonance in the music. Dissonance is not only present in many metal compositions, but its prominence suggests that dissonance is one of the genre’s central aesthetic features, at least in its more extreme subgenres. This is a subversion of the typical values in mainstream popular music, where dissonant features are fleeting points of tension. The article argues that dissonance is valued for its congruence with an aesthetic that transcends the genre through its overall transgressive traits. Such an aesthetic is appealing because it facilitates the exploration of negative emotions and ideas in safety, both individually and communally.