Alright, so... I'm reading about Turntablism and the 2001 movie Scratch on wikipedia. I get what a DJ is and an MC is, one being the person that runs the tracks, the other being the announcer for events...yes i get that. What i don't understand is their comparative existence in rap. For instance, DJ QBert vs MC Hammer. I understand they're just names...but there has to be a more ontological reason for either being a "DJ __" or MC ___. Is one supposed to be analogous (maybe even homologous) to the producer and the other analogous (maybe homologous here as well) to the Singer, or rock star, or whatever you want to call it?

I hope my fusion of geekiness and love of rap wasn't too obvious.