Nah I dont think rap came from pop, Most know that rap comes from jazz and soul. When you listen to peeps like "salt and pepper" they was one of the first to introduce pop/dance to hip hop, Listen to The sugerhill gang... Thats abit of funk mixed wit jazz, Think about it like this... When hip hop started mixing with pop, most Reggae was out the window! Also we gotta remember pop stands for popular.