afternoon  i like rap music
I am not a big fan but I know some stuff about it. It is a musical form that incorporates rhyme rhythmic speech and street vernacular.
i like it because of the rhythm to it, and the unique sound
Cool! It is very similar to spoken word poetry except rap adds music and the other doesn't.
so when did rap started?
I am not sure the very beginning but it definitely predates hip hop music. 
i guess there is a dividing line between rap and hip hop
in time to an instrumental track. Rap is often associated with, and is a primary ingredient of hip-hop music, but the origins of the phenomenon predate hip-hop culture. The earliest precursor to the modern rap is the West African griot tradition, in which "oral historians", or "praise-singers", would disseminate oral traditions and genealogies, or use their formidable rhetorical techniques for gossip or to "praise or critique individuals." Griot traditions connect to rap along a lineage of Black verbal reverence
Rapping
Rapping (or rhyming, spitting, emceeing, MCing) is a musical form of vocal delivery that incorporates "rhyme, rhythmic speech, and street vernacular", which is performed or chanted in a variety of ways, usually over a backing beat or musical accompaniment. The components of rap include "content" (what is being said), "flow" (rhythm, rhyme), and "delivery" (cadence, tone). Rap differs from spoken-word poetry in that rap is usually performed