Metallica & Billy Eichner Try Singing Rihanna's 'Diamonds' in 'Carpool Karaoke' Teaser

Tucked at the very end of Metallica's Carpool Karaoke teaser video is Metallica putting a rock twist on Rihanna's Billboard Hot 100 chart-topper "Diamonds." Frontman James Hetfield is in the driver's seat with comedian Billy Eichner in the passenger's seat and the rest of Metallica in the backseats. 

The unexpected moment is part of Apple Music's new Carpool Karaoke: The Series, which is based on The Late Late Show host James Corden’s popular Emmy-winning “Carpool Karaoke” segment. 

Metallica's episode, which includes an "Enter Sandman" sing-along, doesn't air until Aug. 15, so fans will have to wait to watch the full version of the Rihanna moment.