Metallica drummer Lars Ulrich reckons Lady Gaga would be a good fit and has offered the 'Poker Face' singer a place in the band.
The news comes after the pop icon rocked out with the band at the Grammys with Ulrich saying they've "got a new lead singer" if she's keen.
"Well, a new co-lead singer is a better way of saying it. We were talking earlier about maybe making her a permanent member of Metallica, and being a five-piece from now on, so we'll see."
Even if she's too busy, wherever Gaga is, she will always be welcome to join the boys on stage.
Ulrich's long been a fan, saying she "killed" at the Superbowl half-time show.
"I think that at a time right now where everything in this country is so divisive, the one thing that everybody could agree on last week was that she just nailed it better than anybody ever, so it was awesome."
Metallica are about to embark on the next leg of their WorldWired tour, in support of their latest record Hardwired… To Self-Destruct.