For me (and I'm a musician) it is as essential as sunlight for a happy existence. I could live without it if I had to, but I would be pretty miserable. Nature has music in it, and it doesn't take too great of an imagination to hear it. There is real beauty in an elegant chord progression, or a well-turned lyric, or even just a note that is clear and passionate. It connects me with something both deep within myself and also brings me closer to God.