Lars Ulrich Sits In With Mumford & Sons

Over the weekend, Metallica drummer Lars Ulrich showed up in just about the last place you’d expect – on stage at a Mumford & Sons concert.
Yes, the legendary thrash metal drummer joined Mumford & Sons for a performance of “The Wolf” at Sunday’s Austin City Limits Music Festival.
Metallica has postponed their WorldWired tour after frontman James Hetfield entered rehab last month, cancelling a trip to Australia and New Zealand that was scheduled to begin this week.
Would you have guessed Lars Ulrich was a Mumford & Sons fan? What’s the most unexpected “guest star” you’ve seen during a concert?