I imagine a physicist would invoke entropy to describe the diffusion of pressure waves and vibration into other forms of energy. Neuroscience might explain the propagation of signals from the cochlea into the brain. A psychologist could hypothesise on the influence of music on our mood and ideas. A philosopher might talk about the influence of music on the way we build our society and how that feeds back into our music. In this way, the music never stops, it continues on as echos rippling through through the universe.