anticipation

folk music usually varies from culture to culture, and is heavily influenced by regional identity. Folk incorporates native instruments, like the kora in Africa or the Guitarron in Mexico, and uses established rhythms that occasionally derive from religious customs or spiritual ceremony. Subject matter tends to relate to local mythologies or come from a period of great suffering, like slavery in America or pogroms in eastern europe.

I wouldn't say that rap falls under the banner of traditional folk music because it varies so greatly and takes a lot from previous genres like soul/blues. However, if you look at rap using the contemporary definition of folk, one that loosely defines it as grassroots-esque, then I guess you could make a case for it.