Indeed, violence is the theme of folkmusic going back to Beowulf. And rap as a _form_ certainly qualifies. On the other hand it is one thing to mourn violence, another to craft lessons from it (Tell Ol' Bill, when he comes home, to let them downtown wimmin alone) and something else altogether to glorify it. The only folk song I can think of that does the latter is the Rangers Fight Song, which incites the worst kind of brutality against enemies. But they are a rare exception, where in Rap they seem to be getting more and more the rule.

As for the "hard streets" argument, diarrhea is real, too, but I don't think I'll sing about it. (Not an original line, I'm sorry to say).