It's true that most consider New Yorkers as a bit stand-offish, and I can tell you that, for the most part, it's earned. After all, you don't hear the challange: "got a problem with that?" said very often anywhere else in the world – unless maybe France. But, there is Central Park, and Macy's and Gimbal's and about the highest concentration of difference-tolerant carbon-based organisms found anywhere in the galaxy!
I mean, there was a reason that the "Men In Black" story could only have its setting in New York – it's the only place in the world where the story would be believable! I mean, alien creatures living completely unnoticed amongst the population? Really… they were aliens not wizards like in England.
So, what would happen in, let's say, Salt Lake or Mesquite, if you were in a food court and literally everyone except you broke into a chorus of Handel's Messiah? Or, broke into an opera about passing them a napkin? … Would YOU simply fake it and join in so you weren't the only one left out?
[The odd thing is to note how long it takes simple bystanders to notice that there might be something different… and, to quickly shrug it off afterwards as something they saw every day… and, to figure out how to make money off it.]