Pop music is a genre of popular music originating in the US and UK in the 1950s, designed to appeal to a teenage/young adult crowd. Although the terms “popular music” and “pop music” are often used interchangeably, “popular music” describes all music that's popular. “Pop music,” however, borrows many elements from “popular music,” such as instrumentation from rock and jazz, vocal harmonies from soul and gospel, orchestration from classical, tempo from dance music, and rhythmic elements from hip-hop.
According to Grove Music Online, the term "pop music" "originated in Britain in the mid-1950s as a description for rock and roll and the new youth music styles that it influenced."
In addition, The Oxford Dictionary of Music explains that while pop's "earlier meaning meant concerts appealing to a wide audience ... since the late 1950s, however, pop has had the special meaning of non-classical mus[ic], usually in the form of songs, performed by such artists as the Beatles, the Rolling Stones, ABBA, etc." Technological changes in the 20th century changed pop music. In the '50s and '60s, 45 rpm records for singles revolutionized the distribution of pop songs. Televised performances, first appearing in the '50s, allowed pop stars to have a visual presence. In the '80s, MTV further introduced visually appealing artists to the world, including the King and Queen of Pop, Michael Jackson and Madonna.