Thread title is asking something different to me: music is not necessary when I'm walking in the woods, floating down a river, climbing a tree; or birdwatching, people watching, stargazing, looking at art, or a new baby. Also when I'm reading, it's a distraction.
Having said that, I do recognize when advertisers and the like are trying to manipulate me with music. Most of the time it's rather laughable. Also, for people like me (and many members here) there is no such thing as background music. I have a great deal of difficulty tuning it out.
p.s., I really dislike music pumped into outdoor spaces, like on the sidewalk in front of a restaurant. If it were Bach or Mozart, I might let it slide. Usually, however, it's crap, and an intrusion into my personal sound space.