I had rhythm box in sound menu which come along with Ubuntu 12.04. In order to have good playlist option i moved to clementine music player. after installing clementine in the system, sound menu has both the player option. I tried choosing the default player as clementine in settings. but it do not change anything. problem is when i try to play any music by selecting inside clementine music player. rhythm box also started playing the same music.
I guess removing the rhythm box in sound menu may solve the problem. Please help how to remove or add any app into sound menu in Ubuntu 12.04