Hip-hop - a musical style, a grassroots movement, a cultural community?

I was writing my paper on urban tribes and searching the virtual world on hip-hop, finding this interesting artist named Bomani D'Mite Armah and his work. I have always been attracted by art that is powerful enough to create a cultural movement and somehow change the world, bring joy, awareness and beauty to the world. Especially in music, the truth is that the strongest and most powerful contemporary musical styles have their roots in the streets, slungs, in the dispossessed, powerless and "forgotten" social groups in urban centers. What also strikes me is the unpredictability of these styles, in terms of endurance, possible mixing and development of new styles and real strength as a social movement. There is also the not so beautiful side of it, such as commoditization of artists and art, vulgarity and, above all, low quality productions that always find audiences to keep them going. This is the case with Hip-Hop. While it has a noble and beautiful character of speaking about the social injustices of our world, it has its vulgar side too. The interactive quality of hip-hop, as well as the stories under the improvised, said-as-sung rhythm are so contagious that the style is performed, re-created and reaffirmed elsewhere in both real and virtual worlds: thank you hip-hop poets, rappers, dancers, and social movement crafters!