Loud background music

I have been getting background awful music while watching CBS programs. The music is so laud that you cannot hear the  people speaking on the program which I am trying to watch. CBS is the worse but ABC is now starting with the background music. Why?  What is happening. This has been going on for quite some time and I do not know who to contact.  We have a black box on another TV in another room but have no B lack Box on this TV. I have to choose another station to watch due to this noise.This has been going on for several years and I do not know how to fix it or who to call.