empath is a similarity analysis of the heavy-metal bands listed in the Encyclopaedia Metallum, based solely on reviewer overlap. The similarity scores are approximately the percentage of overlap, adjusted to reduce the effects of both high popularity and small samples. 10468 bands qualify. Various bonus statistics are provided for no especially good reason.
 
All displayed precision is for entertainment only; no statistical significance is asserted. Aesthetic judgments are probably implied, but not mine.