In order to "get" a lot of the acts in the 1960's you had to be "hip", no squares allowed, which to the older generation seemed to be a 'beyond-asinine' concept.
Fast forward to the 90's (the peak of rap as I see it) and substitute 'hip' with 'street cred'; same difference IMO. Also in the 90s Dr Dre dropped which many consider the 'Sgt Pepper' of all rap albums "The Chronic" which also introduced a then unknown Snoop Dogg. And just like many acts of the 60s, various groups spawned sub-genres ie 'psychedelic music', the Chronic in this case brought 'gansta rap' into the limelight and 'American' living rooms and perhaps far worse -behind the closed doors of their kids rooms).
Granted I'm 57 yrs old now (32 when it was released) and I still cringe at some rap lyrics on today's music but production wise the Chronic was -and still is considered a classic. One of my favorites: "little ghetto boy".
Rap always has been about art imitating life, it wasn't until it started imitating itself did it start to lose it's street cred. Take for instance Biggie Smalls who bragged about selling 'rocks' rocks on the street, his mother (a Phd) debunked a lot of that nonsense. Ditto for Tupac who started out as among other things doing ballet . Suge Knight, the most notorious and intimidating of them all was a college grad.
