Music has influenced society in multiple different ways, multiple different aspects. For the most part, it is one of those things that carries over with from culture to culture, with each one having its own version of said music. That is the part that is interesting, and of course this today’s age- chances are there are at least one genre or type of music that people can connect to.
It's just one of those things that is similar to magic almost, a combination of words and sound promoting certain feelings to occur. One song, such as Cut The Cord by Shinedown, can promote feelings of rush, getting pumped. Whereas another, such as Never Too Late by Three Days Grace, promotes different emotions- feelings of sadness and self reflection.
Almost like spells.
One song can capture you, engulf you. Whereas others simply just help pass the time, with time becoming skewed and feeling it goes by faster. They can give you confidence to do that thing or talk to that person. They can make you tap into what you can do, doing that extra rep in the gym.
They can make you scream the lyrics but instead of screams of anger, they can be screams of joy. In concerts, with live music hitting your eardrums, those spells hit you directly. You can “let loose” and enjoy yourself for a change, instead of being worried about that one thing you have been thinking about.
They can be spells of escape, removing yourself from the reality you face. Will they make the problems go away? Sometimes they can or at the very least help you go through and overcome those problems.
Casting them can help you doing an action easier or getting through an action easier.
One’s person spell might not have the same effect on your friend that it has on you; and that's perfectly fine. They have there own music that calls out to them and assists them, in wherever they need them for. And if they do not, they simply have to look for the right spell.
Songs, in the final sense, are spells.