First of all, the essence of the word is voice. The essence of voice is to be heard. Voices are made by listening. On the other hand, it is sound that is not heard.
There is a problem that Berklee, a philosopher of an Irish religionist, had been thinking for a long time. The tree that fell in the forest is a problem of whether it sounded. The answer is “There was no sound”. In short, unless you hear a sound, it is not a sound. It is merely sound waves or vibration of air. If there were no people to listen to, it is no longer a sound. In other words, music that is not heard has no meaning. It is not meaningful, it does not even sound, much less music.