ROCK AND ROLL Rock & Roll started in the 1950s.It was a fusion of electric blues, gospel, and country. In the sixties rock & roll got new styles: soul, surf, folk rock, the British Invasion, hard rock, and psychedelic.
Rap Rapping is fundamentally the rhythmic chanting of lyrics, often set to a beat. Before rap started showing up in the American music scene, people in the Caribbean and in Africa were telling stories in rhyme, and making up beats. This was the beginning of rap. Rap started in the 1970s as a sort of a street art.
In the mid-late 1980s, rap had split into two forms- "hard-core" and "gangsta" acts. By the 1990s, rap songs had become louder and had more complex lyrics.
POP Pop music is a term from music that was popular. The definition of pop is indefinite, because pop music itself is always changing.In the past 50 years the pop charts have been changing and evolving.
Pop music started in the 1920's. Modern day pop includes R&B, just country, jazz, and folk,but it diver ivied from rock and roll. Mainly it's aural and improvised.