Rap or Rap Music, a style of music that first appeared in the mid-1970s as an outgrowth of popular dance music. Developed, as was break dancing, by urban American blacks, its format originally consisted of a disc jockey (D.J.) playing snatches of a record in short bursts, punctuated by rhythmical scratching of the needle on the record, while a "rapper" sang or recited in fast, slangy, rhymed lyrics.

Originally popular with a limited audience, especially in discos, by the early 1990s rap had become part of the American mainstream, with albums regularly among Billboard's top 40 charts and with rap slang and fashions permeating teenage culture. Both black (Run-DMC) and white (Beastie Boys) rap groups spread rap's early popularity. Although rap lyrics often dealt with harsh subjects such as gangs, drugs, and crime, rap's mainstream popularity was typified by such lighthearted artists and groups, black and white, as MC Hammer, Vanilla Ice, and Jazzy Jeff and the Fresh Prince. Rap music also became the subject of widespread criticism and controversy because of sexually explicit lyrics by such groups as 2 Live Crew, which was charged with obscenity and acquitted. Other rap groups and artists, such as Public Enemy, NWA (Niggers With Attitude), Ice-T, and Ice Cube, were criticized for glorifying violence (especially towards women), graphic sex, and extremist political views.

Typically in rap music, vocalists recite rhyming lyrics in time to a beat that may be sampled from pre-recorded music by other groups. Black youths developed rap music on the streets of inner cities in the United States during the 1970s, but the style has expanded to include a wider variety of performers and audiences. The rap group Run DMC, shown here, was a powerful early influence in the genre. The group helped bring rap music into the mainstream when it released "Walk This Way" (1986), a song first recorded by the well-known heavy-metal band Aerosmith.