He hates music?
Paris, Aryanna Dumbdee, and now Vegas were all concert massacres. I'm excluding Orlando because it was a nightclub. The bad guys have targeted nightclubs since the 70s, as far as I know.
the next shoe to fall concert wise: rap/hip-hop or raggae concerts, where there will be few to no off-duty cops, firefighters, and emts. As a result, the death count will be higher.
or hotel windows?
Taliban hate music...