Pop music as a genre is best defined by that changeable canon of music driven by advertising, appeal, and audience. The dynamic nature of pop music means that the canon is constantly changing. Pop hits are those that receive the most radio airplay, sell the most CDs or are subject to the most music downloads, among a number of other metrics that gauge current popular music.
Another unique factor is the lack of genre boundaries that confine pop music. At any one time a pop music playlist might include hard rock, alternative rock, crossover country, crossover Christian, soul, rap, and R&B. In fact pop music might best be described as a barometer of current musical and social culture.
Pop music through the ages has included classical artists such as Beethoven, Mozart and Bach. In the 30s and 40s swing and jazz artists like Benny Goodman and Duke Ellington topped the pop charts and in the 50s and 60s pop music embraced doo-wop and Motown—Stevie Wonder, The Supremes, The Temptations—and early soul and R&B—Otis Redding, Sam Cooke, Wilson Pickett. Pop rock favs were The Beach Boys, Elvis and The Beatles.
A youth-centric audience is the key to pop music culture. Youth of course comprise that segment of social fabric most influenced by current culture. Music determines trends in fashion, art, television, and even technology. More mature audiences typically have their own tastes established and are less likely to be swayed by overt advertising and marketing ploys.
The musical make-up of pop music is its ability to offer infectious beats, melodies and charismatic artists. This is the number one reason alternative genres often crossover into pop music territory. For example, contemporary Christian bands such as Creed and Jars of Clay have crossed over into the pop charts with addictive singles that have mass appeal. Rap and hip-hop artists Outkast and Black Eyed Peas have done the same with more watered down, danceable grooves that hit a wider audience. MTV and VH1 made music marketable through visuals. Sex surely sells and so it remains a primary theme in pop music.
Long running pop artists currently include Christina Aquilera, Mariah Carey, Madonna, Justin Timberlake, Avril Lavigne, Nelly Furtado, Gwen Stefanie, Beyonce, and Red Hot Chili Peppers. This short list alone embraces sub-genres of alternative, dance, R&B and post-grunge/hard-rock. One of the leading sources for the current pop hits are the Billboard charts, which are updated weekly.