The tradition of unexpected collaborations at the Grammys will continue this year with Metallica performing alongside Lady Gaga. As Ken Ehrlich, the executive producer of the Grammys telecast, explains, it was drummer Lars Ulrich who first suggested teaming up with the recent Super Bowl halftime performer. “I was talking to Lars, and obviously talking about the Grammys, and said, ‘Who do you think you’d want to do something with?’ He came out and he just said, ‘We love Lady Gaga, that would