Sweet grandpas are a dime a dozen. Everywhere you look, there they are: tending to their gardens; waving at cars; handing out butterscotch candies to the kids in the neighborhood. (Boring!) But once in a blue moon, a grandpa comes along who shatters the mold — defying expectations by learning how to skydive, say, or use an iPhone.

John Hetlinger, an 82-year-old former Navy pilot, is one such grandpa, and he’s taking the world by storm.

On June 7, Hetlinger appeared on NBC’s hit show “America’s Got Talent,” a kill-or-be-killed proving ground for aspiring musicians, to sing a song. Wearing a white polo shirt and a pair of khakis pulled up to his nipple line, Hetlinger unleashed a hot-blooded rendition of Drowning Pool’s 2002 classic death metal ballad, “Bodies.”

The reaction from the audience was mixed, with some people shielding their ears from Hetlinger’s terrifying banshee screams, while many jumped to their feet in a fist-pumping frenzy. Nevertheless, the performance earned Hetlinger a standing ovation — and even a little smile from the evil Simon Cowell, America’s gatekeeper of dreams.   

Watch his epic performance below.