The title of this conversation sounds like the title of a thriller (or a children's story).
I agree about the constant background (more like foreground these days) music. What is even more irritating is that even when there are no other customers in a restaurant, café or hairdresser's, for example, a request for the music be turned off, or at least turned down is usually denied.
The volume of music is usually turned up in pubs when there are few customers a) to attract more customers and b) apparently to encourage what customers there are to buy more drinks. I wasn't clear about the logic of this second intention but it seems that if the volume of music is such that conversation is difficult, people drink faster and require refills more frequently. I just go to another pub (or home).