Metallica's James Hetfield was "livid" after his Grammy Awards performance mishap.
The 53-year-old rocker's vocals were completely inaudible in Los Angeles' Staples Center on Sunday during the group's duet with Lady Gaga because his microphone was switched off.
While the singer overcame the difficulty by sharing the Poker Face hitmaker's mic for the second part of the performance of Moth Into Flame, his bandmates say they've never seen him so angry.
Drummer Lars Ulrich said: "I haven't seen him like that in 20 years."