Rap is an American musical style that emerged during the 1970s and took the music industry by storm in subsequent decades. Influenced by early African American styles such as blues, funk and R&B, rap music is the music of a larger culture and has acted as a forum for social commentary and a form of entertainment for people in urban centers and suburbia alike. Like the musical genres that inspired it, rap music has seen many variations since its inception.
Hip-hop emerged in the South Bronx in New York City during the 1970s. Hip-hop culture, which includes elements such as beatboxing, breakdancing, scratching and graffiti, spawned hip-hop music, of which rapping is an integral part. Pioneers such as DJ Kool Herc isolated the drumbeats in funk and soul records into what are called "breaks," and MCs started shouting out call-and-response vocals over breaks to partygoers, in what was the beginning of rap music.
As rap music exists under the umbrella of a larger culture, it has seen many variations since its inception in the 1970s. Politically and socially conscious rappers such as Public Enemy and Arrested Development rhymed about black pride and nationalism and other social issues. Dr. Dre developed G-funk, a form of West Coast gangsta rap that sampled funk music and accentuated it with squealing synth and female backing vocals. Crunk music emerged in the late 1990s, a form of party music. Alternative hip-hop opened up rap music to live instrumentation and experimental song structures and lyrics.
Barring any specific genre conventions, rap music consists of a rhyming vocal style over looped beats, whether live or instrumental, and 4/4 time signatures. Like the blues before it, rap lyrics often reflect the personal plights of rap artists. Rap lyrics are a form of poetry in that they often contain both internal and external rhymes and accentuate different syllables in a line.
Rap music grew from an isolated cultural movement into an international industry. The Sugarhill Gang released the first major commercially successful rap single, "Rapper's Delight," in 1979. Kurtis Blow was one of the first rap artists to become a mainstream performer, along with Run DMC and LL Cool J. In the late 1980s, rap music's focus turned to gangsta rap, which became incredibly successful. Artists such as Snoop Dogg and Notorious B.I.G. scored big hits on the pop charts. Rap music evolved into one of the most popular genres of music in the late 1990s and 2000s with the help of mainstream artists such as Emimen, Outkast, 50 Cent, Jay-Z and Kanye West.
Because many rap artists emerged from urban centers and grew up in neighborhoods rife with crime and drugs, the lyrics of many rap songs reflect these artists' social conditions. Gangsta rap was the first rap genre to come right out and talk about subjects such as police brutality and drug abuse graphically in its lyrics and, because this genre proved commercially successful, the public started holding rap music as a whole under heavy scrutiny. Some believe rap music glorifies violence, misogyny and drug abuse, leading its listeners to commit illegal acts of their own. Others believe rap music is merely a product of the environment and a commentary on a life that many poor people lead in America's ghettos.