What was hip hop like when it first came about?

When it started, it was relatively clean. Then, gangs began to "sing" hip-hop. It began to change for the worse. The gangs were violent, and then hip-hop got the reputation of being violent. Later, groups created songs that were extremelly inappropriate. The government got involved sometimes because some of the songs were threats to the police. In a nut shell, that is how it chaged.