Metallica's "Enter Sandman" is one of the most recognizable metal songs in the world, and many have covered it but I don't think anybody put as much of their own spin on it like Ghost frontman Cardinal Copia and Candlemass.
The rare performance was in celebration of Metallica earning Sweden’s Polaris Music Prize. At the ceremony, which happened earlier today, Metallica were serenaded with this excellent performance. ThePRP explains the award and what Metallica did with its winnings:
The international award was founded in 1989 and rewards musicians annually for: “significant achievements in music and/or musical activity, or for achievements which are found to be of great potential importance for music or musical activity.” Along with the award comes a prize of 1 million Swedish krona ($125,000 USD,) which the band have pledged to put to good use via their own charity, the All Within My Hands Foundation.
Here's Metallica accepting the award: