I recall Performance Today/NPR tenure a while back had a report that bears on this discussion.
A high school student did a laboratory experiment with three groups of white rats: one control group had no music, the second listened to Mozart, the third group had Heavy Metal.
First two groups did OK; but had to end the experiment when the third group of rats killed each other!
I suggested to the emcee, Fred Child, that he pursue this further as a matter of some importance, but so far nothing has occurred. I suspect NPR retains proprietary rights and thwarts its intrinsic relevance to all human white rats.

...and don't forget the fans of BOTH classical music and heavy metal. Much more common in my 22-year old daughter's generation. One week the opera, next, black thrash-metal from Xinjiang....