Relevant: TIL that Chicago street gangs today identify themselves by song. By listening to what drill music (a Chicago form of gansta rap) is playing, youths can tell which gang's territory they are in, or even when gangs are working together.

<https://np.reddit.com/r/todayilearned/comments/5t7ig0/til_th...>

A reply to the post:

>Drill rap, possibly the first genre of music that will end up disappearing because its practitioners have killed each other off.