If you want to play musics (MP3 files) in UNIX/Linux platform, you can choose to use XMMS, Songbird, Amarok ,Rhythmbox and others. Since I use Gnome window manager on my Centos 5.4, I use Rhythmbox to play MP3 music files. However when I first run the Rhythmbox program, I got error messages telling me that ‘The Gstreamer plugins to decode MP3 files cound not be found”, so I need to install the plugins.
The plugins you need are gstreamer-plugins-ugly and gstreamer-plugins-bad. Both are already in RPMforge repository.
Make sure that you already have rpmforge repository. See http://wiki.centos.org/Repositories to know how to install the RPMForge repository.
Run yum to install the plugins:
$ sudo yum install gstreamer-plugins-ugly gstreamer-plugins-bad
After installation succeeded then re-run the Rhythmbox and you should be able to playing MP3 files now.