Music

Music's purpose can't be narrowed down to one thing. Music stands as a way for entertainers to tell a story, to send a message, to doing millions of different things. It serves the purpose of inspiring creativity, helping concentration, or allowing others to escape this world, as well as a million other purposes. Music has been inspired by history, or it has changed history.
A perfect example (and very interesting to read about) of music that changed history lies in the "spirituals," slaves sang in the United States, the songs they sang allowed slaves to, in a way, give encoded messages to each other. As time goes on music changes and evolves, as well as new forms being born. It has reaches all over the world making it possible for everyone to find the fit that they enjoy the most.
In the media world, music is a huge, important, tool. Allowing people to send a message to whoever listens to it. That's not to say that every song needs a message, a common misconception of music is that it exists only as a way for artists to send a story or message. But, it can be used purely for entertainment, to have good music doesn't mean it needs a deeper meaning.