Music?

why does music affect me the way it does? why does each quarter note, half rest, and accent dig into each layer of my skin? why can music change my mood no matter the situation? i often wonder why music has to remind me of people. how one single song can be ruined after a loved one has left. the song that once brought me true happiness and reminded me of them, now it just reminds me of them. the giggling, smiling, understanding every feeling and movement about each other. it brings it all back. why? why does it have to? in an instance my eyes fill with water as the first note strikes.