Performing at last weekend’s virtual BlizzCon on Twitch, Metallica’s heavy metal music transitioned quite suddenly.

Live steaming platform Twitch has received a fair amout of backlash over its lack of a real music licensing system. When users on YouTube upload videos that contain copyright protected music, a claim is automatically filed and monetization revenue is sent to the rightsholder.

Unfortunately Twitch doesn’t have a similar system in place. If copyright material is detected, DMCA notices are issued, with videos usually either muted or takendown. This issue only grew last year as Twitch’s watch-hours hit record highs when stay-at-home orders came into place.

After being postponed in 2020 from its usual November date, Blizzard held their annual gaming convention BlizzCon last weekend as a virtual-only event. Metallica first performanced at BlizzCon in 2014, but this year’s appearance took a turn for the hilarious for some viewers.

While those that tuned in live on Blizzard’s own Twitch and YouTube channels heard Metallica’s 1984 tune For Whom the Bell Tolls, those watching the feed on Twitch’s in-house Gaming feed heard the song replaced by what The A.V. Club called “the dorkiest, most Zelda forest-ass music imaginable”.

It seems Blizzard’s music performance rights did not extend past its own channel. Rather than cutting off the live stream or muting the audio, Twitch’s copyright system decided to play the least Metallica music in its library. To watch the real full performance, click here.