This is a great topic and I want to add a few things.
As Vera pointed out, and plenty of other people have pointed out, NLM IS media. They own it ALL; the recording studios, the equipment in it, the producers, the artists, the radio airwaves, the broadcast equipment, every single channel on TV, the Grid and last but not least, the artists. They are a monopolistic cartel. If an artist wants anyone other than people within immediate earshot to hear their music, NLM is going to get some slice of it.
I have had the good fortune to roleplay with a couple of really good artist PCs. One of them really stands out specifically because of the way they roleplay the challenges of being an artist. They want to record, they want to get their music out there, but they don't want to work with NLM. They want to buy the equipment, but they can't afford it. Because of that, they have pretty much resigned themselves to never really making it. A part of their character is dead inside because they have a dream, but they will never achieve it. That is how all pervasive NLM is. Even a "popular" (in terms of practically every PC in the game knows of them) character is never going to make it... unless they bow down to NLM.
On the subject of music in general, music is a universal language. There are some tones and melodies that make people feel good. Others that make people feel edgy. Others that are soothing. etc. Just think of how films use music is an integral part of a movie or show. Or how lullabyes all follow a familiar, sing song melody that appeals to and soothes children. Music transcends NLM. Even though a character might HATE NLM as a corporation, it is practically IMPOSSIBLE for them to NOT like NLM music. Because music is music, and people are people.
It's a bit easier to not like the programming. The visual media. The news. The shows. Plenty of people realize that it's called television "programming" for a reason. As another poster pointed out, NLM would definitely be using NLP (Neuro Linguistic Programming) to target content to the respective markets. Some people are attuned to that and will consciously opt out.
But....Those same people will likely nod in agreement with a haphazardly put up poster on the wall of the maglev station that decries "Fuck television! Fuck the Grid!" while not realizing that the poster is part of guerilla marketing campaign paid for by NLM. And that the poster is there so that the cameras can track who nods, or otherwise exhibits body language cues of acceptance to the message. Videos which are then analyzed by AI video analysis algorithms to categorize Citizens with potential anti-corporate bias.
In a controlled environment like Withmore, it is impossible to escape the media and NLM. 99.99% of people in Withmore are not going to think about why they like that new song with the catchy beat. They're not going to question why the pop music channels have commercials for beauty products and clothing, or why the angry death metal channels advertise neXus armor.