I hear some people in my personal life sometimes say that they only like a few genres or one specific genre of music like just rock, hip-hop, or classical. This didn't make much sense to me though because if they can't at least somewhat enjoy most, if not all genres of music, then is music not truly universal?
Different genres of music are still music, aren't they? If someone enjoys only one style of music, they still enjoy music, no?
Everyone has to eat, but not everyone likes the same food. What does that tell us? Food is universal (for us, at least). The various cuisines, not so much.
Different people will, quite understandably, like different things. Moreover, our musical taste - especially in younger years - tends to be socially determined, to some extent. Here in Poland we have a joke about this (going back to a film comedy from the Seventies): "How can I like a song I am hearing for the first time?"
Our musical taste will be, at least partly, based on what music we are most exposed to. This, in turn, will depend on our social circle. In some peer groups, certain genres are held in esteem, whilst others are met with disdain. Humans are social animals and we want to fit in. In the case of popular music, we are often presented a package that includes a lifestyle, a set of values - even a political stance, perhaps. All of those things will have an effect that goes beyond the music itself.
That said, professed genre boundaries are more flexible than people are ready to admit - especially as we get older and many things we once considered of supreme importance (such as: what music am I listening to) are put in perspective.
If I may offer a personal anecdote: years ago, I used to play shanties at a sailor pub. One time, the barkeep played a huge pop/disco hit for us - one that I was aware existed, but had not heard before, for lack of listening to the radio. We had a good laugh about the lyrics (which were pretty silly, I have to admit) and then he told us to guess where he had the recording from. The answer: the metal pub downstairs (which hosted a regular "disco night for headbangers" that was insanely popular).
In short, music as a form of entertainment is (mostly) universal. This does not mean that all music has universal appeal. Also, people's claims regarding what genres they are willing to accept need not be taken at face value.
No, obviously not. Universal means, that to there is no (or at least no strong) correlation to ethnicity, just being of ethnicity A does not mean, you can't like music from a composer/ performer with ethnicity B. As always, statistics allow no statement whatsoever on an individual. From my experience friends of classical music may like Jazz, but won't buy pop albums, even if they may hear it during a car drive.