judaspriest.com

For the first (and likely only) time in human history, Judas Priest followed in Justin Bieber's footsteps on Sunday night with an appearance on The Simpsons. Bonus coolness: Their cameo was part of an episode penned by writer-director all-star Judd Apatow, which fans and critics are saying is the best ep of Season 25 by far.

judaspriest.com

The story focuses on Homer's foray into pirating movies and subsequent fleeing to the Swedish embassy when the FBI puts the heat on him. Priest pops up when a Will Arnett-voiced FBI goon uses the British heavy metal legends' sonic assault as a weapon to blast the Swedes out of their embassy.

Rob Halford & Co. bark out "Respecting the law—copyright law" to the tune of their British Steel classic "Breaking the Law," but it fails to drive anyone out of the building. After all, there's only one thing the Swedes love more than socialized healthcare, and that's heavy metal.

Watch Priest get animated below and see if you can guess who the first band to guest on The Simpsons was. Hint: They're from Boston and they know Moe. If that doesn't help, the answer is beneath the video. 

Answer: Aerosmith were the first band to appear on The Simpsons. They were in Season 3's "Flaming Moe's."