Lady GaGa took to the stage with Yoko Ono on Saturday night (02Oct10) to duet at a tribute concert for late Beatles legend John Lennon.
Lennon's widow organised three nights of shows in Los Angeles over the weekend (01-03Oct10) to mark what would have been the musician's 70th birthday on 9 October (10).
Stars including Sonic Youth's Kim Gordon, Thurston Moore and rapper RZA all appeared at the Plastic Ono Band gig on Saturday night (02Oct10), but the highlight of the evening came when the Poker Face hitmaker joined Ono for a duet.
After the concert Gaga took to her page to tell fans about the show, posting a picture of herself posing with Lennon's son Sean, writing: "I got to sit in as a guest musician tonight, what a legendary band + mother, Yoko."