It’s BBM, cause brothers don’t AIM anymore
A reference to the rise of the Blackberry empire and the decline of AOL and AOL Instant Messenger.
At the same time, it’s a great double entendre, because he’s also saying that the hip hop game has made a shift from traditional, gangster rap (like when his father, one of the OG’s, was pivotal to the game) to a different form of the genre. When he says brothers don’t AIM anymore, he means that not as many rappers are actually out there in the streets shooting guns (although everyone’s still rapping about it, because the streets were where gangster rap was born.)
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