Its an interesting idea but be sure that it works in the way you are intending. The very essence of a 'scream' is that it is chaotic. Its pure terror arising spontaneously out of sudden unpredictable events and a complete lack of control. By putting these expressions in a musical 'order' you can run the risk of diluting their power. This kind of thing can easily spill over into comedy.

An option might be to use musical sounds that have some characteristics of a scream - bowed string instruments can produce some very eerie scream-like sounds. Another might be to use real screams but carefully built into an almost subliminal non-tonal texture behind the music.