If you don't think it's musical, that says more about   your musical taste than it does about rap--Your may respond to, say, Bill Monroe, or Gordon Lightfoot, instead, and nothing wrong with either of them, but there are a fair number who claim that neither one are real music, let alone folk music. I've certainly heard it said--and it really means that whoever says it just doesn't like them.

There are lots of different kinds of folk and traditional music in the World, and many many, many of them feature drumming and chanting--which is probably why Rap/Hip Hop have been embraced all over the world.