Metallica were joined by Lady Gaga for a performance of their track, "Moth Into Flame", at the 59th annual Grammy Awards in Los Angeles on Sunday.
The pairing suffered through a technical glitch by producers when James Hetfield's microphone failed to work during the first verse, forcing him to share Gaga's with her as they ploughed through the blazing track from their No. 1 album, "Hardwired…To Self Destruct."