In reply to Fruit:
Whilst doing geological field work eons ago near Loch Eriboll I heard someone playing some kind of pipe absolutely beautifully. Just a few phrases, then it would stop, then a few minutes later it would restart. I walked over to where the sound seemed to be coming from, but couldn't see anyone. This happened on about three separate days; I never saw a soul. I don't (generally) believe in ghosts, so I suppose this person just liked to operate surreptitiously.
I can't stand canned music in the wilds though. I like to listen to the sounds of nature. Also, I don't understand why someone would want to listen to music with headphones on in the great outdoors, however fond of music. Natural sounds are one of the dimensions of nature. Birdsong is a wonder to behold.