-People do a lot of hand-raising and swaying at post-rock shows.
That is not an inherently Christian behavior. I mean for crying out loud, the pot-smoking free-love hippies did that in the sixties, and I would hardly think they invented it either.
Pot smokers tend to love post-rock too. When I saw Explosions in the Sky I could smell someone smoking weed on the actual floor of the venue. It was so crowded that they knew security couldn't catch them, which was the case since I never saw anyone get thrown out.
It's more notable here to go to a post-rock/mathsrock gig and NOT smell weed