This could have been a very short article. What is pop music? It’s music that’s popular. Bam. Done. But there is a big difference between popular music and “pop” music, although they do overlap many times (which probably contributes to the confusion).

Popular music has ostensibly been around since people have been listening to music at all: Find the songs that the most people like, and you’ll find popular music. I chose to use the definition from the New Grove Dictionary of Music, which is a source of musical information agreed upon by musicologists. They identified the term “popular music” as we use it today as originating in the 1800s. The definition isn’t all that surprising: it’s the type of music most commonly associated with the industrial middle class. This is why art music, colloquially but inaccurately called “classical music,” isn’t generally considered pop.

The mainstream quality of the music defined it throughout the 20th century. But now we’re arriving at what “pop” music is, born after communication technology. Some researchers even ignore the earlier definition and place the birth of pop music in the 1950s, overlapping the birth of rock-and-roll music and jazz. This identification makes more sense to me partially because I can relate to 1950s pop more easily than I can 1800s pop. But to a certain extent the 1950s definition is more satisfying because it identifies elements of the music itself separate from its actual popularity. You can differentiate rock from folk, ragtime or electro-funk. But pop isn’t just rock, is it? Do you hear a lot of rock songs on the radio today? Hell, there are some who think that rock as a genre is dead entirely.

That point leads into a disappointing reality of pop music: Its definition is constantly changing. If pop can be rock and then not-rock, contain elements of blues but not be blues, what could possibly make pop a standardized genre instead of a synonym for popular music?

It’s actually a pretty hard question to answer, and not everyone agrees. Some believe there are actual musical genre elements that define pop and that other genres just don’t fit. I don’t quite agree with such a restrictive definition. Pop seems to have a close relationship with commercialization and record companies that have no real loyalty when it comes to the genre of music in question; they simply sell what people are buying, or what they think they’ll buy.

What I (and professional smart people like Theodore Adorno) think makes pop distinct is based more on its structure than its content. What I mean is that most pop songs today are three to four minutes long, have repeated choruses or refrains, and have melodies designed to attract listeners. In addition, pop songs are made to stand alone, sometimes even in fragments; how many times have you heard the last refrain of a pop song and recognized it as part of the full piece? It’s all about the hook.

Who knows what form pop will take in the near future? The fragmenting of genres of music and overlapping of electronica and hip hop are both processes that might make pop music almost unrecognizable in 20 years. Bottom line? Wait for the drop.