XMMS2 (X-platform Music Multiplexing System 2) is a new generation of the XMMS audio player. It is a new design, written from scratch, separate from the XMMS codebase.

These are the steps to install XMMS2 in ubuntu
1) Enable all the sources in software sources (Ubuntu->System->Administration->Software Source->Ubuntu Software), Then close it. It will ask you if you want to refresh and click ok.

2) Open the terminal (Alt+F2 then gnome-terminal). Type:
sudo apt-get install xmms2 esperanza

Esperanza is my choice of client interface of xmms2.

3) When everything is install its time to test it. Alt+F2 then esperanza, a prompt will appear to ask you where you want to connect and ignore this and click on connect.
There you go, its a playlist with one default song,.

To add songs:
Just press the +, you can add files, folders, url and search medialib

Note:XMMS2 and esperanza is at its young stage so there might be so bugs, error and crushes you might encounter.