Though there are noise ordinances in cities, some neighbors can't get a clue about the noise they make. So call them out with this letter without getting into a fight worthy of Springer. Hopefully the noise issue will resolve itself without the neighborly drama.
Its me Eric from 208-B. I do want to talk to you personally about this, but as you know I work odd shifts at the hospital and I really come home very tired at night. Lately, the noise level from your unit is becoming a problem in our building and I'm not the only one who took noticed. However, the other tenants have asked me to bring this to your attention since we're on the same floor.
I would like to kindly ask if it would be possible to tone down the music during the evening and on school nights. I'm also a big fan of Cher and her music, I wouldn't mind hearing your playlist in the daytime or on weekends. I hope you understand our concern.