I'm frustrated with my roommate that stays in the room directly next to me and plays music late at night. Should I just tell him to stop?
Are you sure he's not just watching tv or something?
I'm sure it's playing music, because I can hear the rhythm and lyrics.
Wanting some peace and quiet at night is completely understandable. If your roommate is disturbing you, you should feel free to tell them so. Hopefully he listens and is more considerate in the future.
Nah, I'm going to be passive aggressive about it.
Being passive aggressive about the noise will almost definitely not bring an end to the problem. You need to have a direct conversation with them instead and bring the issue to their attention. Otherwise, your roommate may never even understand what the real problem is, so they won't be able to fix it.