I'd use muzak--oddly enough, I wouldn't think of capitalizing it despite the fact that I know the word's origin and have read about the company--to refer to any bland, canned background music. If you mention muzak, though, I'll think about the music in a shopping mall, in an office building's waiting area, or especially that encountered in an elevator.
I've noticed Muzak-brand equipment apparently in still in use on a couple of occasions: you may see a metal plate, something like the faceplate on a wall socket, with the label Muzak Co. or the like.