Dear roommate,
I was asleep 11 in the morning and you were playing your music so loud. It really pissed me off. I want to throw my pillow to you to make you realize someone's sleeping. I don't even know if you know or you're just so insensitive enough to make it so loud. I know it is already 11 am and mostly people would be likely up already but except me. And I do think you should remember that.
Next time,it would be nice if you see first that you won't disturb anybody.
Sincerely.