Although Lady Gaga and Metallica gave a performance that brought the house down at the GRAMMYs on Sunday, there were some mishaps. Lead singer James Hetfield?s mic wasn?t working, so he had to share with Lady Gaga. Nevertheless, they made it through the performance as professionals. However, on The Late Late Show on Tuesday night, drummer Lars Ulrich revealed that the reaction backstage was very different. Lead singer James Hetfield was upset.