© Carl Redhead/epa/Corbis
It's fair to say Metallica's collaboration with Lou Reed has been met with a fevered response. But, take a look below to see why Lars Ulrich reckons without such baffling musical hook-ups Metallica would wilt and die.
The diminutive Dane told USA Today (opens in new tab): "People would like us not to stray beyond certain boundaries. That would kill Metallica. We feed on freedom. We love coming back to metal, but we need to turn over rocks or we'd suffocate. That's our DNA."
So there you have it, accept Lulu or watch Metallica slip to the other side. The choice is yours.