The Foo Fighters frontman went solo for an acoustic show at the Cannes Lions festival in France on Wednesday night (22Jun16), and before launching into his band's hit Best of You, Dave recalled the time Taylor came to his rescue at a house party.

Dave recalled being at the bash when Paul, who he deemed "the baddest motherf**ker on the planet," decided to get on the piano for an impromptu performance. After playing a new tune for the guests, Paul looked at Dave and said, "'Come on, Dave! Play a song!'"

The former Nirvana star began to freak out because not only did he not know how to play piano, but he didn't feel comfortable strapping on any of the available guitars, since they were all fitted for left-handed MCCartney.

On top of that, Dave admitted to being under the influence of marijuana, and as he became even more frazzled, Taylor saved him by coming up from the audience and offering to play a song.

"I was like, 'Oh thank God! Taylor Swift is here. Like f**king Batman when you need him!'," Dave said. "So she gets up at the piano and I thought, 'OK, I'll jam with her. So I pick up one of Paul's left-handed basses, I'm super high, she starts playing, and I'm just trying to figure out how to play along with her. It was kinda like one of those nightmares where you're running backwards."

He continued, "She was playing this really beautiful song on the piano. I look at my wife and I'm like, 'I know this f**king song.' And she was f**king playing our song Best of You. As if I weren't high enough that f**king blew me into outer space. I just lost my mind. So I felt obligated to sit next to her and duet."

"She's got a good voice she can sing. So I sat next to her and did this..." as Dave belted out his version of Best of You for the Cannes crowd.