Xmms

From LXF Wiki

Xmms, the X Multimedia System, is a popular music player. Currently, the stable releases uses GTK 1, but a spinoff project called BMP uses the newer GTK 2 toolkit. Xmms looks and behaves much like Winamp, and can even use some of its themes. You can get various plugins for Xmms to play a variety of music formats, including MODs and Mega Drive .gym files.