$ sudo apt-get update
$ sudo apt-get install gxmms2 

gxmms2 is installed in your system.

Make ensure the gxmms2 package were installed using the commands given below,

$ sudo dpkg-query -l | grep gxmms2 *

You will get with gxmms2 package name, version, architecture and description in a table

gxmms2 package basic information: