$ sudo apt-get update
$ sudo apt-get install csmash-demosong 

csmash-demosong is installed in your system.

Make ensure the csmash-demosong package were installed using the commands given below,

$ sudo dpkg-query -l | grep csmash-demosong *

You will get with csmash-demosong package name, version, architecture and description in a table

csmash-demosong package basic information: