I usually listen to the game's BGM to set the mood, but I often tone it down, because it's too loud for me. I remember turning it up one time, when I was playing Uuultra C, because I was enjoying it a lot. It felt to me like the music was an unseparateable part of the storytelling. Maybe next time in the future, when I find the BGM too bland, I'll turn it off completely and let some cat or duck jazz video play in the backgroud instead.