For me...
What Music is... Is too complex to be descripted in a few words... But if I have to explain what it is for me, Music is the result of all the frequencies that are floating around this beautiful universe, that are aglomerated in a comprehensive sound for humans, that means that everything is music, but not every human distinguish all the sounds as music, because they're acculturated to the patterns imposed by the old harmony, music is when you hear in the early morning the birds, music is a tree leaf falling into the floor, music is the deepest silence of the deepest hole, music is the sound of the air that we breath...
Music is Life coming, and music is life passing away in front of your eyes, when you're a child everything is so intense and when you grows up everything that used to be intense is now common, that's the music of life...
If you really want to know what music is, first you gotta be prisoner of time and realize who you really was, and then you would be free and able to recognize what music really is...

I Salute you, and have a beautiful day full of love.^_^