Headcannon: Despite being a bloodthirsty demon who's possessing a human Rahzun has a strange liking to Opera music if its dark cause it tends to make his mood better at times he does have a all time favorite Opera music

Phantom of the Opera

Favorite song Music of the Night

Rahzun will hum this while being alone and while possessing Americus he will sing it out aloud

Oh yeah did I forget to mention that Americus/Jester  has a good singing voice? Well he does

Now you know