I won't pretend to understand the subtle nuances which distinguish metal subgenres but I went to high school, alright, I know the penalty for getting it wrong. Apparently, so do the writers of The Simpsons, who have apologised to Judas Priest for referring to them as death metal when - obviously - they are, in fact, heavy metal.

The Guardian reports that the gaffe came in a recent episode in which Homer gets nicked for illegally downloading music, leading the FBI to hire Judas Priest to re-write their song Breaking The Law to become an anti-piracy anthem.

The episode had caused outrage among metal fans.

"I don't care if you want to have fun at metal's expense," said Stereogum's Michael Nelson, "but if you brazenly mix up black metal and death metal - and the essence of the joke hinges on getting that reference right - well, that's just lazy writing and it deserves to be called out and mocked relentlessly. But that's totally pardonable compared to calling Judas Priest a death metal band."

Incidentally, a past guest star of The Simpsons, Weird Al, was once erroneously credited with doing the same thing to another heavy metal band, transforming Metallica's Enter Sandman into Enter Napster. (Apparently it was actually done by another cover artist called Johnny Crass.)

To make reparations, The Simpsons' writers had Bart scrawl on his blackboard "Judas Priest is not 'death metal'."

Judas Priest will release a new album later this year. Watch the band on The Simpsons below. And in other Simpsons news, they recently paid homage to Japanese filmmaker Hayao Miyazaki with a sequence referencing a number of his films, which you can see here.

-The Vine