If you could put on a set of headphones that gave you a superpower, what superpower would you choose? For a lot of us, it's probably safe to say invisibility. Laugh if you must, but we didn't choose it randomly. Just watch how people act when they're plugged into their music. That sound they're pumping into their ears may make them feel transported away or isolated from all the people and things happening around them. But tunes and a good pair of headphones won't make anyone invisible.
Part of the appeal of invisibility is the state of being unobserved — free from worry about social rules. But tuning out the world isn't an excuse to forgo common courtesy. Invading personal space, bumping into people, or ignoring outsiders because you can't hear them over your music aren't anyone's idea of good manners.
We have basic rules of etiquette to help guide us comfortably, rather than embarrassingly, through social situations. You'll notice a common thread running through even the most basic rules of etiquette: Acknowledging and being considerate of other people is always good form. So even if you're lost in the musical wonderland of your favorite melodies, remember that you still need to be courteous to others.