Research has shown that music can elevate the emotions of someone; music can either make you sad, happy or angry. However, when you are emotionally low, music can distract you from whatever you are sad about, try listening to a song from genelec musicians friend that makes you happy and sing along to it. Another reason is that sometimes people can relate to the music they are listening to. Maybe something is happening in their life and that song just speaks directly to it. Having music that relates to what you are thinking is like knowing that there is someone out there that understands.