Above, Bart's "apology" on behalf of The Simpsons writers for referring to Judas Priest as "death metal" in a previous episode which infuriated the group's very vocal fans. From The Guardian:
The original slur came in a storyline where Homer starts illegally downloading music, leading to an anti-piracy investigation from the FBI and an escape to immunity in a Swedish consulate. The FBI counter by hiring the "death metal" Judas Priest to blast a piracy-themed rework of their track Breaking the Law, with the words changed to "Respecting the law: copyright law!""The Simpsons apologise to Judas Priest for calling them 'death metal'"