What about the old tradition of talking blues...is that music. I'd certainly like to think so.

As for the boasting and bragging, rap grew out of a sort of battle of the DJ's. In the same way that groups would compete in break dancing, rap was a sort of competition. Most of the time when a rapper is boasting and bragging he is boasting about his skills as a rapper...of course gangsta rap also involves boasting about virility. Think of each time Ulysses (greek not irish) each time he introduces himself he lists all of his accomplishments and tells everybody how great he is, and every time he meets a woman....and its all done in rhyme