>>149062842 Live Crew's "We Want Some Pussy" i remember kids singing it in grade school and knew it was all over at that moment
I listened to rap prior to that and it was just about waxing emcees, stylin' and profilin', so if you want to get specific, 1986, but if you want to get more technical, 1985 with songs like Schoolly D's "PSK What Does It Mean?"
https://youtu.be/m1mn9m_1h5U which was probably the first rap single to use the word "Nigga". 1986's "Triggerman" by Showboys was probably the first gangster rap single
https://youtu.be/8P5k6EiK0Rc