Hip hop music (also referred to as rap or rap music) is a style of popular music. It is made up of two main components: rapping (MCing) and DJing (audio mixing and scratching). Along with breakdancing and graffiti (tagging) these are the four elements of hip hop, a cultural movement that was initiated by inner-city youth (mostly minorities such as African Americans and Latinos) in New York City in the early 1970s.
Typically, hip hop music consists of one or more rappers who tell semi-autobiographic tales, often relating to a fictionalized counterpart, in an intensely rhythmic lyrical form making abundant use of techniques like assonance, alliteration, and rhyme. The rapper is accompanied by an instrumental track, usually referred to as a "beat", performed by a DJ, created by a producer, or one or more instrumentalists. This beat is often created using a sample of the percussion break of another song, usually a funk, rock, or soul recording. In addition to the beat other sounds are often sampled, synthesized, or performed. Sometimes a track can be instrumental, as a showcase of the skills of the DJ or producer.
Hip hop began in New York City when DJs began isolating the percussion break from funk and disco songs. The early role of the MC was to introduce the DJ and the music and to keep the audience excited. MCs began by speaking between songs, giving exhortations to dance, greetings to audience members, jokes and anecdotes. Eventually this practice became more stylized and became known as rapping. By 1979 hip hop had become a commercially popular music genre and began to enter the American mainstream. In the 1990s, a form of hip hop called gangsta rap became a major part of American music, causing significant controversy over lyrics which were perceived as promoting violence, promiscuity, drug use and misogyny. Nevertheless, by the beginning of the 2000s, hip hop was a staple of popular music charts and was being performed in many styles across the world.