During a Metallica rehearsal at the band's headquarters in San Rafael, California, James Hetfield launched into a brief, impromptu version of Ghost's "Cirice." You can check out a clip of the cover above.
Hetfield has long been a fan of the band, telling Sweden's SVT in 2011 "I had no idea what they looked like until I saw the video. I heard the music first and I thought it was very great very unique, very melodic and a breath of fresh air for metal. It reminded me a bit of Seventies kind of rock that I liked as well. So yeah, I love the band."
Ghost's new album, Prequelle, will be released next Friday, June 1. You can preorder it right here.