Public Enemy's Chuck D and Hank Shocklee discuss how copyright law affected the creative approach of rap: How Copyright Law Changed Hip Hop
Back in the day, things was different. The copyright laws didn't really extend into sampling until the hip-hop artists started getting sued. As a matter of fact, copyright didn't start catching up with us until Fear of a Black Planet. That's when the copyrights and everything started becoming stricter because you had a lot of groups doing it and people were taking whole songs. It got so widespread that the record companies started policing the releases before they got out.