Music becomes popular when it is commercially distributed to a large audience and thus perceived by the so-called mainstream culture (Shuker, 2001). Nowadays one can hardly escape pop music - it is played in supermarkets, in public toilets and you catch yourself humming along with a song on the radio that you thought you "hate". This all adds to some sort of an undeniable group experience that one has when listening to music. Pop music aims for a collective audience, individualism might be indicated but in the end the industry is about money and reaching as many people as possible. At this point, the question to what extend the music itself matters arises. I think that music is so deeply connected with culture that you cannot separate it from social groups, family values, clothing and fashion, or emotions and experiences. Especially on an emotional level, songs are often connected to certain memories, and suddenly the semiotics of this song become individual as you remember your first kiss or the day of your graduation from high school when a particular song comes up. Those songs carry a special meaning for one person, often despite their usual taste and can continue to do so for many years, long after the popularity of this song. It becomes clear that emotions might be the trigger to whether a certain genre or a song is considered valuable or not. Those emotions can be partly acquired (e.g. (grand)parents "teach" you that classical music is of high value and belongs to our cultural elite, or your group of friends consideres a certain type of music "cool"), and are often connected to a sense of belonging.
Shuker, Roy (2001). Understanding Popular Music (2nd Ed.) Routledge.
Two concepts of popular culture were "invented" throughout the 19th, and into the 20th century by intellectuals of Romanticism, folklore and folk song, defining popular culture as a "quasi-mythical rural 'folk culture', and the other [...] was popular culture as the degraded 'mass culture' of the new urban-industrial working class" (Storey, 2003, p.1). This two-way definition is still visible today: while some would consider pop music as a genre in itself and recognizing it as a part of our culture, others degrade this fact and try to distance themselves of all kinds of 'mass culture', regardless whether they might like one song - if it is popular, it is suddenly not worth as much anymore and presumably also represents one's personality as less individual or special.
The mediation processes of popular music nowadays are quite different to just a decade ago. While it is easy to become nostalgic and to miss self-made mix tapes made by friends for your birthday, it is also striking to be able to share and access songs so quickly and directly. YouTube is known for having opened up a sphere where everybody can become famous without a record label, but rather discovered by other individuals. One can now browse through all kinds of music and thus get to know different genres or bands from all over the world on their own account, being less dependent on the decisions that the music industry, our family or friends, or the supermarket around the corner make when it comes to finding that certain song or artist or genre that connects with your personality and emotions.
A genre in itself?
References
Shuker, Roy (2001). Understanding Popular Music (2nd Ed.) Routledge.
Storey, John (2003). Popular Culture as Folk Culture. In: Inventing Popular Culture. Oxford and Carlton: Blackwell, pp. 1-15.

