It amazes me how many still think this thread is a serious question vs being for fun and hypothetical. Go back to page two and you will see the OP's response about the issue.
I would have to AGREE with Ron. the siren and air horn should be the only music playing. If you are listening to anything else, I would not want to be around if you had an accident and AC/DC or something like it was on the radio.
Sigh ... please read older posts where it shows the OP changed it to theoretical and not real. I think the initial bit was a matter of how it was worded. The OP is from Germany and I doubt his first language is English. No professionals would do something so assinine while responding to a call!!