Hi and welcome in the Music plugin's readme.
First of all, thank you to use this plugin and I hope it will be useful.
To work with your prefered player, the plugin require some things to do.
Currently, the Music plugin supports many players : ITunes (Mac), WinAmp, Windows Media Player (Windows), Amarok, Audacious, Banshee, Exaile, Juk, Listen, MPD, QuodLibet, Rhythmbox, Totem and XMMS (Linux).

ITunes :
- You don't have anything to do it works immediately. Just go to the plugin's config to make Music plugin at your taste ;) Don't forget to set a nickname in the plugin config if you don't want to just have the song name as nickname.

WinAmp :
- Normally it's like ITunes : it works immediatly.

Windows Media Player :
- You need MSN Messenger installed and its plugin enabled in WMP

XMMS :
It's a little more complicated than the others (just a little ;))
- you must install xmms-infopipe if it isn't. To know, go to the preferences of General plugins and see if it is.
Else, you can get it from http://www.xmms.org/plugins.php?details=212 or http://www.beastwithin.org/users/wwwwolf/code/xmms/infopipe.html.
You can also get it for your distro from the www.rpmfind.net site.
- once that you did it don't forget to activate it in the preferences window !

Totem :
- You need to install the last version of Totem to make sure that the functionnality is installed (Thanks to Karel and the Totem team to make it for us)

Songbird:
- Songbird needs the dbus extention available at http://addons.songbirdnest.com/addon/181
