18-time Grammy winner Paul McCartney admitted he didn t recognize his own guitar when he first heard his 2015 collaboration FourFiveSeconds with Rihanna and Kanye West. I didn t even know I was making a song, the legendary 78-year-old said on Thursday s episode of The Tonight Show Starring Jimmy Fallon. It just went on for a couple of days, and it was only two months later when I got a track sent to me. I didn t think I d done anything, but suddenly I got sent FourFiveSeconds with Rihanna. I didn t even know I was making a song! 18-time Grammy winner Paul McCartney (L) admitted he didn t recognize his own guitar when he first heard his 2015 collaboration FourFiveSeconds with Rihanna (M) and Kanye West (R)