At the 1975 Grammy Awards.

David Bowie, Art Garfunkle, Paul Simon, Yoko Ono and John Lennon 
at the Grammy Awards, 
New York, 1975.

Photo: Ron Gallela.

Hey John, who's that girl?

John, Ringo, and something more on the left that happens to be Yoko's hair. Just look at Ringo's face when he realized that she was there to go out with them (and the guys on the back laughing at him).