Rap is a vocal style, usually combining with Hip Hop. Rapping itself, also known as "emceeing", "MCing", "spitting", or just "rhyming", is a rhythmic spoken delivery of rhymes and wordplay that grew out of the 1940s Scat style of singing, and would definitely owe a nod of thanks to the Blaxploitation movement.
A great example of Scat style vocals by Ella Fitzgerald from 1969 -
Rap is also considered a separate genre from Hip Hop, in some cases where the artists do not make music compatible with the Hip Hop culture. Rap music has a general focus on pop, and snap beats, while Hip Hop has a general focus on the other three pillars of Hip Hop, these would be DJing, graffiti, and breaking.
We did stumble upon this, from an Italian vocalist in 1972, very much before its time -
As well as Blondie and Rapture