The last time we saw Lady Gaga was on Sunday, when she literally dropped the mic after an impressive halftime performance at the Super Bowl, then dove offstage. She’s going to reappear on a stage this weekend, but with Metallica. Late last night, a fan posted a snippet of a Grammys commercial that says “Lady Gaga duets with Metallica.” While some Metallica fans will probably cry foul, Gaga is no stranger to metal. She loves Iron Maiden and Judas Priest, and says her favorite metal song is “Black Sabbath,” which, if you consider Sabbath the first metal band, is technically the first metal song. She also listed Metallica’s Kill ’em All as one of her favorite albums on iTunes’ failed social network Ping (remember that?) back in the day.

What song will they duet on? That’s where things get interesting. It’d be unsurprising if they went with “Enter Sandman,” since it’s a song that even non-Metallica fans know. We wouldn’t be too surprised if it was “Nothing Else Matters,” either, since there’s ample room for harmonizing. The last time we saw Metallica on the Grammys back in 2014, they also collaborated, playing “One” with classical pianist Lang Lang. So basically, what the Grammys are trying to say is that Metallica isn’t worthy of getting their own segment. At least they’ll be paired with another superstar.

The 59th Annual Grammy Awards air this Sunday (12) on CBS. The bands up for best metal performance include Gojira, Periphery, Megadeth, Korn and Baroness.