Pop music is a music genre that developed from the mid-1950s as a softer alternative to rock 'n' roll and later to rock music. It has a focus on commercial recording, often orientated towards a youth market, usually through the medium of relatively short and simple love songs. While these basic elements of the genre have remained fairly constant, pop music has absorbed influences from most other forms of popular music, particularly borrowing from the development of rock music, and utilizing key technological innovations to produce new variations on existing themes.

Musicologists often identify the following characteristics as typical of the pop music genre:

•    a focus on the individual song or singles, rather than on extended works or albums
•    an aim of appealing to a general audience, rather than to a particular sub-culture or ideology
•    an emphasis on craftsmanship rather than formal "artistic" qualities
•    an emphasis on recording, production, and technology, over live performance
•    a tendency to reflect existing trends rather than progressive developments

The main medium of pop music is the song, often between two and a half and three and a half minutes in length, generally marked by a consistent and noticeable rhythmic element, a mainstream style and a simple traditional structure. Common variants include the verse-chorus form and the thirty-two-bar form, with a focus on melodies and catchy hooks, and a chorus that contrasts melodically, rhythmically and harmonically with the verse. The beat and the melodies tend to be simple, with limited harmonic accompaniment. The lyrics of modern pop songs typically focus on simple themes – often love and romantic relationships – although there are notable exceptions.

According to Simon Frith pop music is produced "as a matter of enterprise not art...is designed to appeal to everyone" and "doesn't come from any particular place or mark off any particular taste." It is "not driven by any significant ambition except profit and commercial reward...and, in musical terms, it is essentially conservative." It is "provided from on high (by record companies, radio programmers and concert promoters) rather than being made from below...Pop is not a do-it-yourself music but is professionally produced and packaged."

Source: http://en.wikipedia.org/wiki/Pop_music