Viewers of America’s Got Talent are well aware that one can never really guess what’s about to happen next. And yet, even with this knowledge it doesn’t seem like the audience nor the judges were ready for what was about to happen when John Hetlinger hit the stage.

Hetlinger, an 82-year-old man from Broomfield, Colorado explained to the judges that after retiring from a career in aerospace engineering 15 years ago, he finally got into karaoke. During the short conversation, it was clear to see that Hetlinger is sweet, fun-loving old man but what wasn’t clear was his eclectic taste in music.

By the looks on the judges’ faces, as well as the audience’s reaction, it seems fair to assume that no one expected to hear Hetlinger perform a hardcore rock song. The 82-year-old dove right into an extremely unexpected cover of Drowning Pool’s 2001 single “Bodies,” proving yet again that we should never judge a book by its cover.

Watch the performance above.