From The Art and Popular Culture Encyclopedia
Pop music, often called simply pop, is a common type of popular music (distinguished from classical or art music and from folk music. The term, which was coined as a genre in 1954, does not refer specifically to a single genre or sound, and its meaning is different depending on the time and place. Within popular music, "pop music" is often distinguished from other subgenres by stylistic traits such as a danceable rhythm or beat, simple melodies and a repeating structure. Pop song lyrics are often emotional, relating to love.
The standard format of pop music is the song, customarily less than five minutes in duration, with instrumentation that can range from an orchestra to a lone singer. Pop songs are generally marked by a consistent and noticeable rhythmic element, a mainstream style and traditional structure. Rare variants are 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.