Elton John and Lady GagaOn Thursday, Lady Gaga joined Bruce Springsteen, Elton John, Sting, Mary J. Blige and Blondie's Debbie Harry onstage at New York's Carnegie Hall to perform at Sting's annual Rainforest Fund benefit show. The 21st annual show opened with Sting singing 'Englishman in New York.' Next up was Gaga, who performed 'Stand By Me' and was joined by Sir Elton John on her next song, 'Speechless.'

But absolute chaos erupted on stage at the end of the night when all the stars gathered to perform Journey's classic anthem, 'Don't Stop Believin'.' There are no words to describe the carnival of delights that ensued, including verse-swapping by Lady Gaga and The Boss and later, a squad of Speedo-wearing dancers high-kicking and nuzzling on Sir Elton. You. Must. Watch: