People communicate through musical expression. They can use that expression to relieve stress. They can use that expression to share thoughts and emotions to others that cannot easily be conveyed though spoken word. They can also mean nothing at all except that ones mind has become idle.
That is the problem with song. Most of the time the words are not your own. They are a frame of reference created by another mind. It means something to you or it says something that you want others to hear. But even worse than spoken word, a stolen bit of song losses much in the space between your mind and another.
Art is a window into a soul. Make your own.