Several points:
1. I've been to Africa and listen to the music that Africans make and listen to. I did not notice any similarity to the US-produced commercial music known as hip hop or rap. So describing the latter as "the black" music looks to me like cultural imperialism, racism or both. It is similar to saying that country and western is "the white people's music," and boasting that white singers occupy ten top positions on lists in Texas or Tennessee.
2. I would resist using the sweeping labels like "kids today." When my kid was in high school he and his friends listen to a lot of rap, watched a lot of violent flicks etc. - which I did not particularly appreciated but respected because they were careful not to violate my boundaries (i.e. blast this shit when I was in the house). One thing that make me tolerant of it, though, was the fair certainty that _my_ kid will go to college and his infatuation with juvenile contumacy expressed in much of pop culture (especially punk and hip hop) will be soon forgotten. I was right - my kid went to a private college while his HS buddies, well, they still live in the hood with "their" hip hop. I think it is a sad commentary on this society's inequalities, which the "let them have their culture" crowd seem to ignore.
3. I find particularly pathetic is a bunch of self-styled kultur-uber-alles progressives who see pop culture is the most important act of social protest and take no-so hidden pleasure when it pisses off the old white men. It is pathetic because when the dust settles, these kids will be living in their noise... err cultural expression engulfed hood, whereas the pissed off white men will be even more inclined to live in communities where the boom-box carrying youth will be promptly arrested should they choose to show up there.
If progressivism, radicalism, leftism etc. means that that I haveto quietly consent to a bunch of kids blasting stuff in my face whether I want listen to it or not - you can keep your "ism." I am not buying.
Wojtek