Someone playing music at a shelter makes me want to re-enact the Animal House scene with Belushi smashing the guitar against the wall. I am probably not the only one who doesn't want to listen to fiddle music while trying to rest.
http://www.vidilife.com/video_play_2...itar_Smash.htm
Of course, if you offer Jim Beam before hand, then by all means play away.
Just ask before you start up. A little courtesy goes a long way. Just think how many people on these boards/ on the trail would be spitting mad and bent out of shape if someone came into the shelter with a stereo / boombox and fired that up for all to hear. It would probably go over like a lead ballon.