When I look for a definition of music, I take the Edgard Varèse approach by using the simple definition that music is organized sound. I feel that is the most simple and open definition for me.
However most people I have talked to take the "misty-eyed" romantic approach to defining music. Usually their definition contains phrases as "the most expressive art form for the human emotion" or "Divine gift from the Heavens" and such.
All this attempts to define music, though usually fruitless in any attempts to sway public opinion on the subject, promoted me to ask the following questions to my fellow composers on this forum:
What is YOUR working definition for music?
Is a definition of music needed or is it a personal subject?