I don't know if this is possible or if an addon even exists for doing this, but I was wondering if there is some way you to share the music you are listening to (say on itunes) with the group your playing with in wow? If someone knows please let me know, I would love my group to raid to some awesome music of my choosing :)

addons are not allowed to run outside of WoW at all   (short answer is Never will be a addon to do any non WoW related things)

If it even was possible and allowed, kinda egocentric to force your music on others ain't it? I know my guild members listen anything from classical to rap and hardcore and in 80% of the cases those who like one type, don't really like the other.

well I was discussing it with my group that I normally play with and they were cool with it, just though it would be a fun idea

Well in theory it is possible but it would not be sharing so much as one person being in charge of a playlist. You could have an addon that EVERYONE would need in the group to be installed in order to control the music playing on the other end and it would also be limited to whatever music the addon had installed. This all has to be contained inside the addon.

You can not play music on your end and have it play on the other side (thank god). While the people in your circle of friends may think that is cool can you imagine PUGging and having one person play something like Slavic folk music and having it play on your end. Ewwww. No offence to the Slavic folks out there :p

Lol teek, that would be a nightmare beyond imagining for me. But if you could have say 5 people all have 1 addon, 1 person queue's up the music playlist, and each person must manually hit "play" to listen, and sync in with the main playlist holder, that would be cool. Forcing it on others, weither they say "yeah lets do it" or "no thanks" woudl be wrong, but giving them the ability to play/stop it at their choosing wouldn't be too bad.

I think there was once an addon, whose name eludes me, that you put the music files in the addon folder and you could play it in game.. but I think this was pre-TBC and from what I understand addons have been limited since then.

There are MP3 players for WoW yes.  You have to play the music you want to listen to into a specific folder and then the addon can control the music from within the game.  The addon doesn't control an MP3 player but rather it *IS* the MP3 player (the game does support mp3s which is why the addon works).  Some of the mp3 addons did have the ability to output your current song's name into chat but there is no way you can make others listen to the same music unless they have the music physically on their hard drives also.  that being said, it could be possible to issue a command from an addon that would make other users of the same addon hear a song.  NECB and an addon called Wipe Music used to do this.  If you typed in /wipe, all the users with that addon would hear whatever was the programmed wipe sound.  NECB also had things like the X-files theme, Jaws music and more.