I don't think that there is a way you can change it. I go to the options area on the little thing that comes up in the sims, you know, the ... thing. When looking on the options I've never seen anything that looked like it would turn off that. Maybe I'm not looking hard enough, I never actually looked for it. I think the only way you might be able to do what you want to do is turn off the sound when the ghost music is playing and then turn it on again when it is done. But that would be a pretty annoying thing to have to do.