Metallica vocalist James Hetfield suffered microphone troubles last night as the band performed “Moth Into Flame” with Lady Gaga as the 59th annual Grammy Awards show at the Staples Center in Los Angeles, California.

Sources connected to the production tell TMZ, that everything was fine right before the performance.

“Gaga and the band's line check, right before the performance, went off without a hitch. However, between the mic check and their act, a wire under the stage got unplugged. We're told a stagehand did it by accident, but the damage was done - Hetfield's mic was dead through most of the performance. They eventually fixed the unplugged wire with seconds left in the song. We reached out the Grammys, but no word back yet.”

Stay tuned for updates.

Meanwhile, Metallica are featured in a video trailer for Apple Music’s upcoming Carpool Karaoke series. Based on the segment that has become a global, viral video sensation on The Late Late Show with James Corden, the new series features 16 celebrity pairings riding along in a car together as they sing tunes from their personal playlists and surprise fans who don’t expect to see big stars belting out tunes one lane over.

As well as Metallica, the series will feature James Corden, Will Smith, Billy Eichner, Alicia Keys, John Legend, Ariana Grande, Seth MacFarlane, Chelsea Handler, Blake Shelton, Michael Strahan, John Cena, Shaquille O’Neal, and many more.