<human>:  What is the history of hip-hop music?
<bot>: Hip-hop music is a style of popular music which originated in the United States in the late 1970s. It is rooted in African-American culture and is closely related to other elements of hip-hop culture such as rap, break dancing, and graffiti. The earliest predecessor of hip-hop is the West African music genre known as Kool Herc, which was developed in the early 1970s by Jamaican-born musician Clive Campbell. The sound was characterized by rhythmic speaking which emphasised the syncopation of beats and samples, pairing them with MCing and DJing. By the mid-1970s, much of what would come to be labeled hip-hop had been developed by a broad array of African-American performers from cities such as the Bronx and Brooklyn, New York. It wasn't until 1979 that the term "hip-hop" was officially used to describe this new emerging subculture. From the 1980s onwards, hip-hop has grown significantly, both in terms of regional popularity and global influence, becoming one of the most popular music genres in the world today.