Rapping, also referred to as MCing or emceeing, is a vocal style in which the artist speaks lyrically, in rhyme and verse, generally to an instrumental or synthesized beat. Beats, almost always in 4/4 time signature, can be created by looping portions of other songs, usually by a DJ, or sampled from portions of other songs by a producer. Modern beats incorporate synthesizers, drum machines, and live bands. Rappers may write, memorize, or improvise their lyrics and perform their works a cappella or to a beat.
The roots of hip hop are found in African-American music and ultimately African music. The griots of West Africa are a group of traveling singers and poets who are part of an oral tradition dating back hundreds of years. Their vocal style is similar to that of rappers. The African-American traditions of signifyin', the dozens, and jazz poetry are all descended from the griots. In addition, musical 'comedy' acts such as Rudy Ray Moore and Blowfly are considered by some to be the forefathers of rap.
Within New York City, griot-like performances of poetry and music by artists such as The Last Poets, Gil Scott Heron and Jalal Mansur Nuriddin had a significant impact on the post-civil rights era culture of the 1960s and 1970s.
Hip hop arose during the 1970s when block parties became increasingly popular in New York City, especially in the Bronx. Block parties incorporated DJs who played popular genres of music, especially funk and soul music. DJs, realizing its positive reception, began isolating the percussion breaks of popular