Soundpack music plays while listening to mp3

[Entity-y]

To enhance immersion, have the soundpack's background music play only while listening to mp3 or stereo. The distance to the stereo could alter the volume to give the illusion that the music is being played further away. Something like this would need to be a toggleable setting, which also suppresses the "you listen to some..." messages or at least change the descriptions to be less specific.