"'Anthem' in this context can also be read as 'emblematic.'”
I don't see any definition of anthemic that equates the word with "emblematic" without also implying positivity -- e.g., "the song is considered an anthem of the civil rights movement." And I don't know of any anthems for countries, or cities, or whatever that stress the negative aspects of those places, as WSS is primarily about the tribalistic hatred that causes gang warfare that leads to murder of people who would love each other under different cirucmstances. I agree with the other poster who noted that WONDERFUL TOWN or ON THE TOWN are two shows that would be much more accurately describes as "anthems of," or perhaps "odes to," New York City.